Influence of ECAP passes on Zn–Li–Mn alloys: mechanics, corrosion, and osteogenesis

Introduction: Biodegradable zinc is a promising base metal for temporary orthopedic fixation; however, its insufficient strength has limited its use at load-bearing sites.

Methods: We designed a Zn–Li–Mn system and refined its microstructure by equal-channel angular pressing (ECAP). The number of ECAP passes was tuned to investigate its effect on mechanical and electrochemical properties.

Results: Increasing the number of passes resulted in significant improvements in mechanical response, reaching an ultimate tensile strength of approximately 450 MPa with favorable elongation (up to 76.6% at 12 passes). Strengthening occurred through a combination of grain refinement, dislocation hardening, and second-phase contributions. Electrochemical tests and long-term immersion in Hank’s solution revealed a progressive enhancement in corrosion resistance, with the average corrosion rate decreasing from approximately 34.60 to 26.66 μm year^-1 between 8 and 16 passes. Microstructural uniformity reduced localized attack at second phases and grain boundaries.

Discussion: In vitro studies with MC3T3-E1 cells confirmed cytocompatibility and demonstrated enhanced osteogenic activity compared to titanium controls. This included increased alkaline phosphatase levels, stronger mineral deposition, and upregulated osteogenesis-related genes. These findings suggest that ECAP effectively optimizes strength, ductility, and corrosion resistance in Zn-based alloys, supporting their potential as next-generation biodegradable implants for orthopedic applications.

1 Introduction

In recent years, zinc (Zn) alloys have attracted wide attention as a new class of biodegradable candidates for load-bearing orthopedic implants (Chen et al., 2024; Li et al., 2024). Compared with magnesium and iron systems, they exhibit more moderate corrosion rates while maintaining favorable biocompatibility (Chen et al., 2020; Bowen et al., 2013). Yet, the limited strength of pure Zn has historically constrained its clinical application (Edalati and Horita, 2011; Wu et al., 2022; Liu et al., 2015; Li et al., 2015). Substantial progress has been achieved through alloying and severe plastic deformation, which markedly improve its mechanical performance (Pachla et al., 2021; Li et al., 2023; Li et al., 2019; Lu et al., 2024; Wątroba et al., 2020). These advances have encouraged exploration of Zn alloys for orthopedic fixation devices (Mostaed et al., 2018; Venezuela and Dargusch, 2019). However, successful translation into clinical use also requires appropriate degradation behavior and sustained biocompatibility. In some cases, high strength has been realized, but corrosion or cellular responses remain insufficient. Thus, the central challenge is to develop Zn alloys that integrate mechanical robustness, controlled resorption, and excellent cytocompatibility.

Alloying combined with plastic deformation remains the most effective route to enhance Zn’s performance. Among alloying elements, lithium (Li) plays a unique role due to the strong strengthening effect of the LiZn₄ phase. Yang et al. reported that adding 0.4 wt% Li increased the ultimate tensile strength (UTS) of as-extruded Zn from 166 MPa to 520 MPa (Yang et al., 2021). Similarly, (Duan et al., 2022) showed that 0.38 wt% Li raised the UTS of Zn-2Cu-0.2Mn from 300 MPa to 445 MPa (Duan et al., 2022). Despite these gains, the trade-off between strength and ductility is pronounced; Zhao et al. found elongation dropped from 14% in Zn-2 at.%Li to 2% in Zn-6 at.%Li. Alloying with manganese (Mn) has been shown to alleviate this limitation, improving plasticity in Zn–Li systems (Shen et al., 2025; Wang et al., 2024; Yang et al., 2024; Yang et al., 2023; Zh et al., 2024). Another route is the creation of ultrafine-grained microstructures, which can markedly enhance ductility. For instance, Zn-Cu, Zn-Mn, and Zn-Ag alloys with refined grains exhibit room-temperature superplasticity (Mostaed et al., 2019; Guo et al., 2021; Guillory et al., 2022). Collectively, these findings suggest that combining Li and Mn alloying with microstructural refinement may offer a balanced pathway toward high strength and ductility in biodegradable Zn alloys.

Equal-channel angular pressing (ECAP) is a particularly promising technique for producing fine- and ultrafine-grained structures (Valiev and Langdon, 2006). Refinement of both matrix grains and secondary phases is one of the few approaches capable of simultaneously strengthening alloys while retaining plasticity (Hansen, 2004). ECAP processing has been applied to several biodegradable Zn-based alloys. For example, (Ye et al., 2022) reduced the grain size of Zn-0.1 Mg to 1.14 μm, with UTS and elongation enhanced to 383 MPa and 45.6% (Ye et al., 2022). Ji et al. (2024) also demonstrated substantial strengthening and improved ductility in Zn-0.06 Mg after 8 passes (Ji et al., 2024). Wang et al. (2021) further observed that 12-pass ECAP refined Zn-0.033 Mg to ultrafine grains, leading to elongation of 25.37% (Wang et al., 2021). Bednarczyk et al. (2019) extended these findings to multiple Zn alloys, achieving grain sizes below 4 μm and elongations exceeding 100% (Bednarczyk et al., 2019). These studies collectively confirm the efficacy of ECAP in refining Zn alloys and enhancing their mechanical response. Microstructures and mechanical properties of Zn alloys after ECAP are mainly influenced by processing passes and temperature. Ren et al. investigate the effect of ECAP temperature on microstructures and mechanical properties of Zn-1Cu alloys (Ren et al., 2021). They demonstrate that the grain sizes of Zn alloys decrease with increasing processing temperature, thereby achieving high tensile strength. Another case on Zn-1.6 Mg alloy subjected to ECAP shows that the increasing passes is beneficial to the refinement of grains and secondary phases (Huang et al., 2020). Thus, high tensile strength is obtained with increasing ECAP passes. Nevertheless, systematic investigations on Zn–Li systems remain scarce, particularly regarding microstructural evolution with increasing ECAP passes.

Against this backdrop, we designed a Zn-0.8Li-0.5Mn alloy and subjected it to 8-, 12-, and 16-pass ECAP at room temperature. The resulting samples were comprehensively evaluated for their microstructural features and mechanical behaviours. In addition, corrosion characteristics, cytocompatibility, and osteogenic potential were assessed in vitro. This integrated study provides new insights into fabricating Zn-based biodegradable alloys with both high strength and substantial ductility, advancing their potential use in orthopedic applications.

2 Experimental procedure

2.1 Preparation of the studied Zn alloys

The as-cast Zn–0.8Li–0.5Mn (wt%) alloy ingots were supplied by the Hunan Institute of Rare Earth Metal Materials. Chemical composition was confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES, iCAP6300, United States), showing actual Li and Mn contents of 0.81 wt% and 0.49 wt%, respectively. The phase components of the as-cast Zn-Li-Mn alloy was characterized by X-ray diffraction (XRD, D8 Discover, Bruker, Germen) at a scanning rate of 2°/min and scanning range from 30°–80°. Rectangular billets (10 × 10 × 90 mm) were cut from the ingots and processed through equal-channel angular pressing (ECAP) according to established procedures (Bednarczyk et al., 2019; Bednarczyk et al., 2018). ECAP with a Bc route was conducted at 200 °C, with specimens subjected to 8, 12, or 16 passes, including a 5 min holding step after every fourth pass. Following ECAP, plates (10 × 10 × 2 mm) were extracted for systematic investigations, including microstructural observations, electrochemical and immersion studies, cellular assays, osteogenic evaluation, and antibacterial testing.

2.2 Microstructural characterizations of Zn alloys

To elucidate the structural features of the processed alloys, multiple advanced techniques were applied. Optical microscope (OM, BX53M, Olympus, Japan), Field-emission scanning electron microscopy (FE-SEM, Helios 5 CX, Thermo Fisher Scientific, United States) and electron backscatter diffraction (EBSD, e-Flash, Bruker, Germany) were used for microstructural mapping. Elemental distributions were analyzed using energy-dispersive X-ray spectroscopy (EDX, X-Flash 7, Bruker, Germany) attached to the SEM. For metallographic preparation, samples were ground, polished, and etched with an ethanol-based solution containing 4 wt% nitric acid. The polished samples are necessary to electrically polish before EBSD. The electrolytes are composed of 50% phosphoric acid and 50% ethanol. The electrically polish process was conducted at −30 °C and 15V for 15–20 s. Step size of EBSD patterns was set as 0.07 μm. Thin foils (1 mm) were mechanically reduced to ∼50 μm using silicon carbide abrasive papers, followed by twin-jet polishing. The solution for twin-jet polishing is composed of 10% perchloric acid and 90% ethanol. TEM samples were prepared at liquid nitrogen environment. Final thinning for transmission electron microscopy (TEM, Talos F200X, Thermo Fisher Scientific, United States) was achieved by low-temperature ion milling (Fischione, United States).

2.3 Mechanical tests

Tensile behavior was evaluated on a universal testing system (Autograph AGS-X, Shimadzu, China) at a constant strain rate of 10⁻³ s^-1. Following ASTM-E8 guidelines, miniature dog-bone specimens with dimensions of 2 × 3 × 10 mm were prepared and tested at room temperature. Fractured surfaces were subsequently analyzed using scanning electron microscopy (SEM) to assess failure morphologies.

2.4 In-vitro degradation tests

Electrochemical behavior was assessed using a standard three-electrode setup connected to an electrochemical workstation. Open-circuit potential was monitored for 3,600 s, followed by potentiodynamic polarization (PDP) scans from −1.4 V to −0.6 V at 0.1 mV s^-1. Both electrochemical measurements and immersion experiments were performed in Hank’s solution for up to 30 days, maintaining a solution-to-sample surface ratio of 20 mL/cm². After immersion, specimens were rinsed with deionized water, air-dried, and corrosion products were removed using a 200 g/L chromium trioxide (CrO₃) solution prior to further analysis. The corrosion rates of ECAPed Zn alloys were calculated from the equation: $v_{corr}=\frac{\Delta m}{\rho AT}$. Where $\Delta m$ was weight loss after removing corrosion products, ρ was the density of the studied Zn alloys, A was the exposed area, and T was immersion time.

2.5 In-vitro biocompatibility evolutions

Cytotoxicity and osteogenic assays were performed with murine pre-osteoblast MC3T3-E1 cells (ATCC). Cells were cultured in α-MEM supplemented with 10% fetal bovine serum (FBS) and 1% penicillin–streptomycin under standard conditions (37 °C, 5% CO₂, 95% humidity). Medium was refreshed every 2 days. Prior to testing, alloy disks were ultrasonically cleaned and UV-sterilized for ≥4 h per side. Extracts were prepared by incubating sterile samples in complete medium at a ratio of 1.25 mL/cm² for 24 h, centrifuged to remove particulates, and stored at 4 °C. Zn²⁺ and Mg²⁺ ion concentrations in the extracts were quantified by ICP-AES (Thermo Scientific M Series, United States).

For viability analysis, cells were harvested by trypsinization, resuspended, and exposed to undiluted or 50% diluted extracts for 3 and 5 days. Cell proliferation was measured using the CCK-8 assay (Dojindo, Japan). Live/dead staining with Calcein-AM/PI was performed, and cellular morphology was visualized with an inverted fluorescence microscope (Zeiss Axio Vert.A1, Germany).

Osteogenic differentiation was examined via alkaline phosphatase (ALP) activity and extracellular matrix mineralization. Cells were cultured in osteogenic medium mixed 1:1 with extracts, with medium renewal every 48 h. After 7 days, ALP staining was conducted; after 14 days, mineral deposition was assessed by Alizarin Red S (ARS) staining following fixation with 3.7% formaldehyde. ARS-bound calcium was visualized and quantified spectrophotometrically. In addition, total RNA was extracted with RNAiso Plus (TaKaRa, Japan), reverse-transcribed into cDNA, and analyzed by qPCR to evaluate osteogenic gene expression.

2.6 Statistical analysis

All experimental data was repeated for at least three times independently, and presented in form of mean ± standard deviation (SD). Besides, the one-way analysis of variance (One-way ANOVA) and the following Tukey’s post hoc test were conducted to manifest the differences between groups.

3 Results

3.1 Phase component and microstructures of as-cast Zn alloys

Figure 1 illustrates the phase component and microstructure of the as-cast Zn alloys. According to the Zn–Li phase diagram, eutectic and eutectoid transformations occur at 401 °C and 65 °C, producing β-LiZn₄ and α-LiZn₄ phases (Liang et al., 2008; Okamoto, 2012). The Zn–Mn phase diagram indicates the formation of MnZn₁₃ phases (Shi et al., 2018). Thus, the studied alloys primarily contain LiZn₄ and MnZn₁₃. XRD patterns (Figure 1a) confirmed these phases, showing prominent diffraction peaks of Zn at (0002), (01 $\overline{1}$ 0), and (01$\overline{1}$ 1) planes (36.5° and 39.1°), alongside peaks attributed to LiZn₄ and weaker signals assigned to MnZn₁₃. OM (Figure 1b) and SEM images (Figures 1c,d) revealed lamellar eutectoid structures, where lath Zn alternates with LiZn₄ (Cao et al., 2023). The lath thickness and spacing ranged between 300 and 500 nm (Figure 1d).

Figure 1

Figure 1. Microstructural characterizations of as-cast Zn alloys. (a) XRD spectrum. (b) Optical microscope image. (c) SEM image with low magnification. (d) SEM image with high magnification.

3.2 Microstructures of Zn alloys after ECAP

OM images (Figure 2a) revealed that after ECAP, the Zn matrix and second phases were elongated along the extrusion direction (ED), forming alternating bands. Low-magnification SEM images (Figure 2b) showed a mixture of dynamically recrystallized (DRX) grains and elongated second phases, appearing as granular and strip-like features aligned with ED. With increasing passes, regions consisting of DRX grains became progressively thinner, and secondary phases were fully refined. Figure 2c highlights second-phase evolution: in 8p- and 12p-ECAP samples, fine particles coexisted with lath structures which were almost absent from the microstructures of 16p-ECAP, indicating complete refinement at higher deformation.

Figure 2

Figure 2. Microstructures of Zn alloys after ECAP. (a) Optical microscope images. (b) SEM images with low magnifications. (c) SEM images with high magnifications.

EBSD analysis (Figure 3) further demonstrated microstructural changes. Inverse pole figure (IPF) maps displayed equiaxed ultrafine grains with varied orientations: red for (0001), blue for (01 $\overline{1}$ 0), and green for ($\overline{1}$ 2$\overline{1}$ 0). DRX was evident in all samples. It can be measured from Figure 3a that the average grain sizes were 1.41 μm for 8p-ECAP sample, 1.36 μm for 12p-ECAP sample, and 0.69 μm for 16p-ECAP sample, respectively. Moreover, the fraction of fine grains (<5 μm) reached 64% for 8p-ECAP, 38% for 12p-ECAP, and 100% for 16p-ECAP (Figure 3b). Kernel average misorientation (KAM) maps (Figures 3c,d) showed average values of 0.75°, 0.90°, and 0.59° for 8p-, 12p-, and 16p-ECAP, respectively.

Figure 3

Figure 3. EBSD analysis of Zn alloys after ECAP. (a) IPF mappings. (b) Grain size distributions. (c) KAM mappings. (d) Local misorientations.

Due to Zn’s low melting point, grain refinement primarily results from dynamic recrystallization (DRX). DRX grains contained fewer dislocations, reflected by low grain orientation spread (GOS <1°). GOS mapping (Figures 4a,b) indicated DRX fractions of 42.9%, 24.2%, and 80.2% for the 8p-, 12p-, and 16p-ECAP samples, respectively, suggesting greater DRX activity at higher passes. Pole figure (PF) analysis (Figure 4c) revealed a pronounced basal texture in ECAP-processed alloys. Texture intensity first increased from 26.21 (8p) to 74.96 (12p), then dropped sharply to 11.05 (16p), consistent with higher DRX grain fractions and reduced dislocation density.

Figure 4

Figure 4. Dynamic recrystallization and texture of Zn alloys. (a) GOS mappings. (b) GOS distributions. (c) Pole figures.

TEM observations confirmed abundant fine phases in ECAP-processed alloys. In the 12p-ECAP sample, selected area electron diffraction (SAED) identified LiZn₄ as the second phase (Figure 5a). High-resolution TEM and SAED also detected MnZn₁₃ precipitates (Figure 5b), frequently located at DRX grain boundaries (Figure 5c). EDS confirmed Mn enrichment in these precipitates relative to the Zn matrix. ImageJ measurements indicated an average precipitate size of 98 ± 29 nm, significantly smaller than the surrounding DRX grains.

Figure 5

Figure 5. TEM analysis of Zn alloys after ECAP. (a) Morphologies of LiZn₄ phase and the corresponding SAED image. (b) MnZn₁₃ precipitates and the corresponding SAED image. (c) The EDS mappings of MnZn₁₃ precipitates.

3.3 Mechanical behaviors of Zn alloys after ECAP

Tensile testing was conducted to evaluate the mechanical performance of ECAP-processed Zn alloys. The representative stress–strain curves (Figure 6a) exhibited clear elastic and plastic stages. In the elastic region, stress increased linearly with strain, followed by a sharp rise to the ultimate tensile strength (UTS), and then a decline. Comparisons of UTS and elongation are presented in Figures 6b,c. The 8p-ECAP sample showed a UTS of 416 MPa, which increased to 433 MPa for the 12p-ECAP and further to 450 MPa for the 16p-ECAP. In contrast, ductility decreased with additional passes, dropping from 76.6% (8p) to 75.2% (12p) and 59.8% (16p). Notably, the 12p-ECAP alloy achieved the most favorable balance between strength and ductility. Fractography (Figure 6d) revealed abundant dimples on the fracture surface, typical of ductile failure, confirming that all ECAP-treated alloys fractured via plastic deformation mechanisms.

Figure 6

Figure 6. Mechanical properties of Zn alloys after ECAP. (a) Tensile curves. (b) Strengths. (c) Elongations. (d) Fractural morphologies. **p < 0.01, ****p < 0.0001.

3.4 Degradation behaviors of Zn alloys after ECAP

Electrochemical measurements are summarized in Figure 7. Potentiodynamic polarization (Figure 7a) and Nyquist plots (Figure 7b) revealed that corrosion potential (E_corr) shifted positively and corrosion current density (i_corr) decreased with increasing ECAP passes. Tafel analysis (Figures 7c,d) showed that the 8p-ECAP alloy had the lowest E_corr (−1.194 V_SCE) and the highest i_corr (10.93 μA/cm²). After 12 passes, Ecorr shifted to −1.188 VSCE with an icorr of 10.53 μA/cm², while the 16p-ECAP exhibited the most positive E_corr (−1.149 V_SCE) and the lowest icorr (8.17 μA/cm²). Nyquist plots confirmed larger semicircle diameters for the 16p sample, indicative of higher charge-transfer resistance. Equivalent circuit fitting (inset of Figure 7b) included solution resistance (R_s), corrosion film resistance and capacitance (R_f, CPE_f), and double-layer resistance and capacitance (R_ct, CPE_dl). The data (Table 1) showed increasing R_ct with ECAP passes, suggesting improved corrosion protection, despite a reduction in R_f values.

Figure 7

Figure 7. Electrochemical behaviors of Zn-Li alloys. (a) PDP curves. (b) Nyquist plots and fitting curves. (c) Corrosion potentials. (d) Corrosion current densities. (e) Corrosion rates calculated from weight loss after immersion for 30 days *p < 0.05, **p < 0.01, ****p < 0.0001.

Table 1

Table 1. Fitting parameters in equivalent circuits.

Immersion experiments (Figure 7e) further supported these findings. Corrosion rates declined from 34.60 μm/year in 8p-ECAP to 32.83 μm/year in 12p-ECAP, and to 26.66 μm/year in 16p-ECAP, confirming enhanced corrosion resistance with additional passes.

Surface morphologies after immersion in Hank’s solution are presented in Figure 8. After 30 days, all alloys developed corrosion films with uniformly distributed cracks (Figure 8a). EDS analysis (Figure 8b) identified corrosion products containing C, O, P, Ca, and Zn. Removal of surface films (Figure 8c) revealed numerous pits characteristic of localized corrosion. The number density of corrosion pits decreased with more ECAP passes. Moreover, the high-magnification SEM images show that the sizes of corrosion pits are a few micrometers and the grain boundary corrosion cracks are observed. In contrast, as-extruded alloys displayed large, irregular pits indicative of severe localized attack. These results collectively demonstrate that ECAP effectively reduces corrosion susceptibility and promotes the formation of more protective surface layers.

Figure 8

Figure 8. Surface morphologies of Zn alloys after immersion for 30 days. (a) SEM images before removing corrosion products. (b) The EDS mappings of corrosion products in 8p-ECAP sample. (c) SEM images after removing corrosion products.

3.5 Cytocompatibility of Zn alloys after ECAP

The biocompatibility of ECAP-processed Zn alloys was evaluated using MC3T3-E1 pre-osteoblasts, with titanium (Ti) serving as the control. Cell viability after 3 days of culture in alloy extracts is shown in Figure 9a. At full-strength extracts (100%), Zn alloys initially exhibited lower activity compared to Ti. However, when diluted to 50%, cell viability improved significantly, exceeding that observed in undiluted conditions. After 5 days (Figure 9b), viability in the diluted extracts stabilized around 100%, confirming good cytocompatibility. Live/dead staining (Figure 9c) further supported these findings: cells cultured in 50% extracts for 3 and 5 days showed green fluorescence indicative of viable cells. Although cell density in Zn alloy groups was slightly lower than that of Ti, cells exhibited healthy morphology and normal spreading behavior, demonstrating that the alloys provided a supportive environment for proliferation.

Figure 9

Figure 9. Cytocompatibility of the studied Zn alloys. Cell viability of MC3T3-E1 cells after culturing for (a) 3 days, (b) 5 days. (c) Live/dead staining images. ***p < 0.001, ****p < 0.0001.

3.6 In-vitro osteogenic properties of Zn alloys after ECAP

The osteogenic potential of Zn alloys was examined through alkaline phosphatase (ALP) activity at day 7 and Alizarin Red S (ARS) staining at day 14. As shown in Figures 10a–d, both ALP activity and mineral deposition were higher in Zn alloy groups compared with Ti, indicating enhanced early osteogenic differentiation. This effect is attributed to the gradual release of metallic ions during alloy degradation, which are known to stimulate bone-forming pathways. Gene expression analysis further confirmed these observations (Figure 10e). In MC3T3-E1 cells exposed to 12p-ECAP extracts, osteogenesis-related markers—including ALP, collagen I (COL-I), osteopontin (OPN), and Runx-2—were consistently upregulated relative to Ti. Collectively, these results demonstrate that ECAP-processed Zn alloys significantly promote osteogenic differentiation, underscoring their promise as next-generation biodegradable orthopedic implant materials.

Figure 10

Figure 10. In-vitro osteogenesis of the studied Zn alloys. (a) ALP staining images. (b) ALP activity. (c) ARS images. (d) Absorbance of ARS. (e) q-PCR results. ***p < 0.001, ****p < 0.0001.

4 Discussion

4.1 Strengthening mechanisms of Zn alloys after ECAP

Previous reports on Zn alloys processed by ECAP or rolling have demonstrated that yield strength (${\sigma }_y$) is mainly governed by grain boundary strengthening (${\sigma }_{GB}$), dislocation strengthening (${\sigma }_{\rho }$), and second-phase strengthening (${\sigma }_S$) (Ren et al., 2021; Huang et al., 2020; Huang et al., 2021; Zhuo et al., 2023). The same mechanisms operate in this work. Severe plastic deformation during ECAP promotes extensive dynamic recrystallization (DRX), resulting in significant grain refinement. This contribution can be estimated through the Hall–Petch relationship (Figueiredo et al., 2023): ${\sigma }_{GB}={\sigma }_0+k{d}^{-\frac{1}{2}}$. Where the ${\sigma }_0$ is the intrinsic strength (32.2 MPa for pure Zn), k (80 MPa μm^-0.5) is the Hall–Petch relation slope, and d is the average grain size (Wang et al., 2021; Diaa et al., 2025). As shown in Figures 11a,b, the DRX grain sizes were 1.41 μm (8p-ECAP), 1.36 μm (12p-ECAP), and 0.69 μm (16p-ECAP), corresponding to σGB contributions of 63.7, 38.3, and 120 MPa, respectively.

Figure 11

Figure 11. Strengthening mechanism of Zn alloys after ECAP. (a) IPF mappings of DRX grains. (b) Grain size distributions of DRX grains. (c) Dislocation densities of unDRX grains.

Plastic deformation also increases dislocation density, which can be estimated from KAM values using (Bednarczyk et al., 2023): $\rho =\frac{2\overline{\theta }}{\mu b}$. Where b is Burger’s vector (0.266 nm) and μ is the tangent line step unit (0.08 μm). Figure 11c shows that non-DRX regions (GOS >1°) had dislocation densities of 17.46 × 10¹⁴ m^-2 (8p-ECAP), 18.50 × 10¹⁴ m^-2 (12p-ECAP), and 11.39 × 10¹⁴ m^-2 (16p-ECAP), as shown in Figure 11c. The strengthening contribution is obtained from (Ma et al., 2014): ${\sigma }_{\rho }=\alpha MbG\sqrt{\rho }$. Where α = 0.2, M = 2.76 (Taylor factor for Zn), and G = 42 GPa.

The calculated ${\sigma }_{\rho }$ values are 147.1 MPa (8p-ECAP), 201.1 MPa (12p-ECAP), and 41.2 MPa (16p-ECAP). Thus, the strength contributions from grain boundary strengthening are smaller than those from dislocation strengthening in the 8p and 12p Zn alloys. For the 16p alloy, the grain boundary strengthening contributes a higher strength value compared with dislocation strengthening. As shown in Table. 2, the measured tensile yield strengths (TYSs) are higher than the sum of strength contributions from grain boundaries and dislocations. This is attributed to the formation of secondary phases, including high fractions of LiZn₄ phases and nanosized MnZn₁₃ phases (Figure 5b). It can be estimated that the strength contributions from secondary phases are 101.2 MPa (8p-ECAP), 34.6 MPa (12p-ECAP), and 168.8 MPa (16p-ECAP), respectively. Consequently, it can be referred that the ECAP passes play a critical role in the transitions of strengthening mechanism. Dislocation and secondary phase strengthening are dominated in 8p- and 12p-ECAP Zn alloys, while grain boundary and secondary phase strengthening are dominated in 16p-ECAP Zn alloys.

Table 2

Table 2. Strength contributions of Zn-Li-Mn alloys after ECAP.

The large number of second-phase particles, including LiZn₄ and MnZn₁₃, also plays a crucial role. These particles can pin dislocations, act as nucleation sites for DRX through the particle-stimulated nucleation (PSN) mechanism, and hinder grain boundary migration, all of which promote ultrafine-grained microstructures (Huang et al., 2018). The superior strength of the 16p-ECAP alloy is therefore linked to this additional refinement. Moreover, nano-sized MnZn₁₃ precipitates at grain boundaries strengthen the matrix through a load transfer effect (Ding et al., 2021). Their deformation incompatibility with the Zn matrix restricts dislocation motion (Azizian et al., 2024) while pre-existing dislocation walls serve as barriers to newly generated dislocations. Together, these mechanisms reinforce the strengthening effect, explaining the high yield strength achieved after 16 passes of ECAP. Table 3 shows the mechanical properties of as-cast and thermomechanical process Zn-Li-Mn alloys (Shen et al., 2025; Yang et al., 2024; Yang et al., 2023; Zh et al., 2024; Yang et al., 2020). The tensile strengths of the majority of Zn-Li-Mn alloys are located in the range of 400–500 MPa after thermomechanical process. After ECAP, tensile strengths of Zn-Li-Mn are below 450 MPa, while the elongations (76.6% for 8p-ECAP sample) are higher than that of most of Zn-Li-Mn alloys.

Table 3

Table 3. Mechanical comparison of the developed Zn-Li-Mn alloys.

4.2 Tuning degradation mechanism through refining microstructures

Weight-loss measurements (Figure 7e) revealed that corrosion rates decreased with increasing ECAP passes. Corrosion in Zn alloys is strongly influenced by grain boundary density, second-phase characteristics, and dislocation density. Grain refinement after ECAP increases boundary density, which can act as preferential sites for corrosion initiation, generally accelerating dissolution (Ralston et al., 2010). However, when dissolution rates fall below ∼10 μA/cm², finer grains instead enhance passivation and reduce corrosion. Electrochemical testing confirmed that the 16p-ECAP sample exhibited an i_corr of 8.17 μA/cm², consistent with this transition. Thus, grain refinement at high ECAP passes inhibits corrosion, explaining the improved resistance observed in the 16p-ECAP alloy compared with 8p- and 12p-ECAP samples. Moreover, dislocation density has a significant effect on corrosion behaviors of Zn alloys. With increasing dislocation densities, the surface energy is elevated, rendering the alloy more susceptible to activation upon contact with corrosive media (Feng et al., 2024). At low ECAP passes, a large number of dislocations are present in 8p-ECAP and 12p-ECAP alloys, which will reduce the corrosion performance. The 16p-ECAP alloys have finer grains and lower dislocation density, which results in superior corrosion resistance.

In addition to grain size effects, phase evolution also plays a role. With increasing ECAP passes, the originally continuous LiZn₄ phases were broken down into dispersed particles, while MnZn₁₃ precipitates were promoted. Previous studies demonstrated that the localized corrosion regions were observed in the regions of secondary phase of Zn-Li based alloys after ECAP (Huang et al., 2024). This is attributed to the occurrence of galvanic corrosion between the LiZn₄ phase and Zn. Although second-phase particles can increase galvanic coupling and accelerate localized attack, their dispersion reduces corrosion sensitivity and facilitates the formation of a more uniform and protective surface film. This film integrity contributes to the lower corrosion rates of highly deformed alloys.

Grain uniformity further influences degradation behavior. As shown in Figure 3, the 16p-ECAP alloy exhibited more homogeneous grain structures, which promoted uniform corrosion rather than localized pitting. Meanwhile, dislocation density decreased significantly with higher ECAP passes (Figure 3c), reducing micro-galvanic activity around dislocation tangles. Collectively, these changes suggest that the beneficial effects of refined, uniform grains and reduced dislocation density outweigh the detrimental influence of second-phase increase. As a result, 16-pass ECAP alloys demonstrated markedly improved corrosion resistance relative to alloys with fewer passes.

4.3 Development of biodegradable Zn alloys toward orthopedic implants

For decades, titanium (Ti) alloys, stainless steel, and cobalt–chromium (Co–Cr) alloys have served as the standard implants in load-bearing sites such as long bone fractures, femoral fixation, and joint replacements (Bandyopadhyay et al., 2023; Cui et al., 2024). These materials share common advantages, including high mechanical strength and reliable biocompatibility. Their tensile strength typically exceeds 400 MPa, ensuring sufficient structural support for bone repair, while their clinical biosafety is well established. Nevertheless, these inert implants present two major drawbacks. First, long-term implantation can trigger complications such as chronic inflammation or persistent pain, often necessitating secondary removal surgery (Reith et al., 2015). Second, their high elastic modulus creates a mismatch with the native bone, leading to stress shielding and progressive bone resorption, ultimately increasing the risk of revision surgery (Shayesteh Moghaddam et al., 2016).

In response, increasing attention has shifted toward biodegradable metallic materials with tailored mechanical and biological performance (Zheng et al., 2014). Magnesium (Mg)-based implants have progressed from laboratory studies to clinical translation after extensive research (Windhagen et al., 2013; Lee et al., 2016). Their in vivo degradation products actively stimulate bone regeneration and accelerate healing (Zhao et al., 2016), providing unique advantages in orthopedic repair. However, the relatively low strength of Mg alloys limits their use in high load-bearing environments.

The Zn–Li–Mn alloy system developed in this study demonstrated ultimate tensile strengths exceeding 400 MPa and elongations above 60%, comparable to Ti while maintaining sufficient ductility. The superior mechanical properties arise from combined contributions of grain boundary strengthening (via fine and ultrafine grains), dislocation strengthening (high dislocation density), and second-phase strengthening. Beyond mechanics, in vitro osteogenesis assays provided further validation. Both ALP and ARS staining confirmed stronger osteogenic induction in Zn alloys than in bioinert Ti, findings supported by the upregulation of osteogenic genes. This enhancement may be linked to the activation of the PI3K–AKT signaling pathway (Yang et al., 2021), a key regulator of bone formation.

Taken together, Zn–Li–Mn alloys integrate the mechanical robustness characteristic of traditional inert metals with the biological activity observed in Mg-based systems. This dual advantage highlights their potential as next-generation biodegradable implants for orthopedic applications, capable of addressing both structural and biological demands in bone repair.

5 Conclusion

This study comprehensively investigated the microstructure, mechanical performance, corrosion behavior, and biocompatibility of Zn–Li–Mn alloys processed by ECAP. Progressive deformation led to significant grain refinement, with DRX grain sizes decreasing from 1.41 μm (8p-ECAP) to 1.36 μm (12p-ECAP), and reaching 0.69 μm after 16 passes. Complete refinement of LiZn₄ phases was achieved in the 16p sample, accompanied by ∼100 nm precipitates distributed along grain boundaries.

All ECAP-processed alloys exhibited tensile strengths above 400 MPa, meeting the mechanical threshold for orthopedic applications. Strengthening in 8p- and 12p-ECAP alloys primarily originated from grain boundary, dislocation, and second-phase contributions, whereas in the 16p alloy, grain boundary and second-phase effects dominated. Corrosion behavior was strongly influenced by microstructural refinement: localized attack and pitting were evident in 8p and 12p alloys, while intergranular corrosion became more pronounced in 16p samples.

Biological evaluations confirmed that Zn alloys after ECAP processing maintained excellent cytocompatibility and significantly enhanced osteogenic activity compared with bioinert Ti. Together, these findings highlight ECAP as an effective strategy to optimize both mechanical robustness and biological performance of Zn-based biodegradable alloys, advancing their potential use in orthopedic implants.

Data availability statement

The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: https://doi.org/10.6084/m9.figshare.30401797.

Author contributions

JT: Writing – original draft, Investigation, Visualization, Funding acquisition. YH: Visualization, Writing – original draft. CY: Investigation, Writing – review and editing, Software, Data curation. ZH: Investigation, Writing – review and editing, Methodology, Formal Analysis. SL: Data curation, Writing – original draft, Software. HL: Writing – original draft, Visualization, Validation, Data curation. JH: Supervision, Writing – review and editing, Conceptualization.

Funding

The author(s) declared that financial support was received for this work and/or its publication. This study was supported by the Hunan Health Commission Research Project (Grant No. 20256263), the Hunan Nursing Association Young Talent Program (2025), and the Hunan Children’s Hospital Clinical Research Program (Grant No. 202302).

Conflict of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The author(s) declared that generative AI was not used in the creation of this manuscript.

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References

Azizian, F., Naffakh-Moosavy, H., and Bagheri, F. (2024). The role of Cu addition in the metallurgical features, mechanical properties, and cytocompatibility of cardiovascular stents biodegradable Zn-based alloy. Intermetallics 164, 108106. doi:10.1016/j.intermet.2023.108106

CrossRef Full Text | Google Scholar

Bandyopadhyay, A., Mitra, I., Goodman, S. B., Kumar, M., and Bose, S. (2023). Improving biocompatibility for next generation of metallic implants. Prog. Mater. Sci. 133, 101053. doi:10.1016/j.pmatsci.2022.101053

PubMed Abstract | CrossRef Full Text | Google Scholar

Bednarczyk, W., Kawałko, J., Wątroba, M., and Bała, P. (2018). Achieving room temperature superplasticity in the Zn-0.5Cu alloy processed via equal channel angular pressing. Mater. Sci. Eng. A 723, 126–133. doi:10.1016/j.msea.2018.03.052

CrossRef Full Text | Google Scholar

Bednarczyk, W., Wątroba, M., Kawałko, J., and Bała, P. (2019). Can zinc alloys be strengthened by grain refinement? A critical evaluation of the processing of low-alloyed binary zinc alloys using ECAP. Mater. Sci. Eng. A 748, 357–366. doi:10.1016/j.msea.2019.01.117

CrossRef Full Text | Google Scholar

Bednarczyk, W., Wątroba, M., Jain, M., Mech, K., Bazarnik, P., Bała, P., et al. (2023). Determination of critical resolved shear stresses associated with slips in pure Zn and Zn-Ag alloys via micro-pillar compression. Mater. and Des. 229. doi:10.1016/j.matdes.2023.111897

CrossRef Full Text | Google Scholar

Bowen, P. K., Drelich, J., and Goldman, J. (2013). Zinc exhibits ideal physiological corrosion behavior for bioabsorbable stents. Adv. Mater. 25, 2577–2582. doi:10.1002/adma.201300226

PubMed Abstract | CrossRef Full Text | Google Scholar

Cao, M., Xue, Z., Lv, Z.-Y., Sun, J.-L., Shi, Z.-Z., and Wang, L.-N. (2023). 300 MPa grade highly ductile biodegradable Zn-2Cu-(0.2-0.8)Li alloys with novel ternary phases. J. Mater. Sci. and Technol. 157, 234–245. doi:10.1016/j.jmst.2023.01.048

CrossRef Full Text | Google Scholar

Chen, K., Lu, Y., Tang, H., Gao, Y., Zhao, F., Gu, X., et al. (2020). Effect of strain on degradation behaviors of WE43, Fe and Zn wires. Acta Biomater. 113, 627–645. doi:10.1016/j.actbio.2020.06.028

PubMed Abstract | CrossRef Full Text | Google Scholar

Chen, K., Gu, X., and Zheng, Y. (2024). Feasibility, challenges and future prospects of biodegradable zinc alloys as orthopedic internal fixation implants. Smart Mater. Manuf. 2, 100042. doi:10.1016/j.smmf.2023.100042

CrossRef Full Text | Google Scholar

Cui, Y.-W., Wang, L., and Zhang, L.-C. (2024). Towards load-bearing biomedical titanium-based alloys: from essential requirements to future developments. Prog. Mater. Sci. 144, 101277. doi:10.1016/j.pmatsci.2024.101277

CrossRef Full Text | Google Scholar

Diaa, A. A., El-Mahallawy, N., and Carradò, A. (2025). Effect of Mg content on the microstructure, texture, and mechanical performance of hypoeutectic extruded Zn-Mg alloys. J. Alloys Compd. 1010, 177155. doi:10.1016/j.jallcom.2024.177155

CrossRef Full Text | Google Scholar

Ding, C., Hu, X., Shi, H., Gan, W., Wu, K., and Wang, X. (2021). Development and strengthening mechanisms of a hybrid CNTs@SiCp/Mg-6Zn composite fabricated by a novel method. J. Magnesium Alloys 9, 1363–1372. doi:10.1016/j.jma.2020.05.012

CrossRef Full Text | Google Scholar

Duan, J., Li, L., Liu, C., Suo, Y., Wang, X., and Yang, Y. (2022). Novel Zn-2Cu-0.2Mn-xLi (x = 0, 0.1 and 0.38) alloys developed for potential biodegradable implant applications. J. Alloys Compd. 916, 165478. doi:10.1016/j.jallcom.2022.165478

CrossRef Full Text | Google Scholar

Edalati, K., and Horita, Z. (2011). Significance of homologous temperature in softening behavior and grain size of pure metals processed by high-pressure torsion. Mater. Sci. Eng. A 528, 7514–7523. doi:10.1016/j.msea.2011.06.080

CrossRef Full Text | Google Scholar

Feng, B., Zhu, K., Shang, X., Chen, Y., Wang, H., Yang, C., et al. (2024). Improving the corrosion and mechanical properties of Mg-8Gd-3Y-0.4Zr alloy synergistically via regulating micro-galvanic corrosion and dislocation density. Corros. Sci. 237, 112275. doi:10.1016/j.corsci.2024.112275

CrossRef Full Text | Google Scholar

Figueiredo, R. B., Kawasaki, M., and Langdon, T. G. (2023). Seventy years of hall-petch, ninety years of superplasticity and a generalized approach to the effect of grain size on flow stress. Prog. Mater. Sci. 137, 101131. doi:10.1016/j.pmatsci.2023.101131

CrossRef Full Text | Google Scholar

Guillory, R. J., Mostaed, E., Oliver, A. A., Morath, L. M., Earley, E. J., Flom, K. L., et al. (2022). Improved biocompatibility of Zn–Ag-based stent materials by microstructure refinement. Acta Biomater. 145, 416–426. doi:10.1016/j.actbio.2022.03.047

PubMed Abstract | CrossRef Full Text | Google Scholar

Guo, P., Zhu, X., Yang, L., Deng, L., Zhang, Q., Li, B. Q., et al. (2021). Ultrafine- and uniform-grained biodegradable Zn-0.5Mn alloy: grain refinement mechanism, corrosion behavior, and biocompatibility in vivo. Mater. Sci. Eng. C 118, 111391. doi:10.1016/j.msec.2020.111391

PubMed Abstract | CrossRef Full Text | Google Scholar

Hansen, N. (2004). Hall–Petch relation and boundary strengthening. Scr. Mater. 51, 801–806. doi:10.1016/j.scriptamat.2004.06.002

CrossRef Full Text | Google Scholar

Huang, K., Marthinsen, K., Zhao, Q., and Logé, R. E. (2018). The double-edge effect of second-phase particles on the recrystallization behaviour and associated mechanical properties of metallic materials. Prog. Mater. Sci. 92, 284–359. doi:10.1016/j.pmatsci.2017.10.004

CrossRef Full Text | Google Scholar

Huang, H., Liu, H., Wang, L.-S., Li, Y.-H., Agbedor, S.-O., Bai, J., et al. (2020). A high-strength and biodegradable Zn–Mg alloy with refined ternary eutectic structure processed by ECAP. Acta Metall. Sin. Engl. Lett. 33, 1191–1200. doi:10.1007/s40195-020-01027-x

CrossRef Full Text | Google Scholar

Huang, H., Liu, H., Ren, K., Shi, J., Ju, J., Wu, H., et al. (2021). Improvement of ductility and work hardening ability in a high strength Zn-Mg-Y alloy via micron-sized and submicron-sized YZn12 particles. J. Alloys Compd. 877, 160268. doi:10.1016/j.jallcom.2021.160268

CrossRef Full Text | Google Scholar

Huang, H., Fang, L., Tong, Z., Gong, G., Yu, H., Kulyasova, O., et al. (2024). Nanostructuring of Zn–Li-based alloys through severe plastic deformation: microstructure, mechanical properties, and corrosion behaviors. Nano Mater. Sci. 7, 697–710. doi:10.1016/j.nanoms.2024.07.004

CrossRef Full Text | Google Scholar

Ji, C., Ma, A., Jiang, J., Song, D., Liu, H., Zhao, L., et al. (2024). Improving the mechanical properties and inhibiting strain softening behavior of the biodegradable Zn-0.06Mg alloy via ECAP plus rolling processing. Prog. Nat. Sci. Mater. Int. 34, 45–55. doi:10.1016/j.pnsc.2024.01.015

CrossRef Full Text | Google Scholar

Lee, J.-W., Han, H.-S., Han, K.-J., Park, J., Jeon, H., Ok, M.-R., et al. (2016). Long-term clinical study and multiscale analysis of in vivo biodegradation mechanism of Mg alloy, Proc. Natl. Acad. Sci. U. S. A., 113 716–721. doi:10.1073/pnas.1518238113

PubMed Abstract | CrossRef Full Text | Google Scholar

Li, H. F., Xie, X. H., Zheng, Y. F., Cong, Y., Zhou, F. Y., Qiu, K. J., et al. (2015). Development of biodegradable Zn-1X binary alloys with nutrient alloying elements Mg, Ca and Sr. Sci. Rep. 5, 10719. doi:10.1038/srep10719

PubMed Abstract | CrossRef Full Text | Google Scholar

Li, P., Zhang, W., Dai, J., Xepapadeas, A. B., Schweizer, E., Alexander, D., et al. (2019). Investigation of zinc-copper alloys as potential materials for craniomaxillofacial osteosynthesis implants. Mater. Sci. Eng. C 103, 109826. doi:10.1016/j.msec.2019.109826

PubMed Abstract | CrossRef Full Text | Google Scholar

Li, G., Chen, D., Mine, Y., Takashima, K., and Zheng, Y. (2023). Fatigue behavior of biodegradable Zn-Li binary alloys in air and simulated body fluid with pure Zn as control. Acta Biomater. 168, 637–649. doi:10.1016/j.actbio.2023.07.030

PubMed Abstract | CrossRef Full Text | Google Scholar

Li, P., Dai, J., Li, Y., Alexander, D., Čapek, J., Geis-Gerstorfer, J., et al. (2024). Zinc based biodegradable metals for bone repair and regeneration: bioactivity and molecular mechanisms. Mater. Today Bio 25, 100932. doi:10.1016/j.mtbio.2023.100932

PubMed Abstract | CrossRef Full Text | Google Scholar

Liang, Y., Du, Z., Guo, C., and Li, C. (2008). Thermodynamic modeling of the Li–Zn system. J. Alloys Compd. 455, 236–242. doi:10.1016/j.jallcom.2007.01.154

CrossRef Full Text | Google Scholar

Liu, X., Sun, J., Yang, Y., Pu, Z., and Zheng, Y. (2015). In vitro investigation of ultra-pure Zn and its mini-tube as potential bioabsorbable stent material. Mater. Lett. 161, 53–56. doi:10.1016/j.matlet.2015.06.107

CrossRef Full Text | Google Scholar

Lu, G., Chen, C., Zhang, D., Guo, L., Lin, J., and Dai, Y. (2024). Optimization of mechanical, corrosion properties and cytotoxicity of biodegradable Zn-Mn alloys by synergy of high-pressure solidification and cold rolling process. J. Alloys Compd. 1005, 175988. doi:10.1016/j.jallcom.2024.175988

CrossRef Full Text | Google Scholar

Ma, K., Wen, H., Hu, T., Topping, T. D., Isheim, D., Seidman, D. N., et al. (2014). Mechanical behavior and strengthening mechanisms in ultrafine grain precipitation-strengthened aluminum alloy. Acta Mater. 62, 141–155. doi:10.1016/j.actamat.2013.09.042

CrossRef Full Text | Google Scholar

Mostaed, E., Sikora-Jasinska, M., Drelich, J. W., and Vedani, M. (2018). Zinc-based alloys for degradable vascular stent applications. Acta Biomater. 71, 1–23. doi:10.1016/j.actbio.2018.03.005

PubMed Abstract | CrossRef Full Text | Google Scholar

Mostaed, E., Ardakani, M. S., Sikora-Jasinska, M., and Drelich, J. W. (2019). Precipitation induced room temperature superplasticity in Zn-Cu alloys. Mater. Lett. 244, 203–206. doi:10.1016/j.matlet.2019.02.084

PubMed Abstract | CrossRef Full Text | Google Scholar

Okamoto, H. (2012). Li-Zn (Lithium-Zinc). J. Phase Equilibria Diffusion 33, 345. doi:10.1007/s11669-012-0052-x

CrossRef Full Text | Google Scholar

Pachla, W., Przybysz, S., Jarzebska, A., Bieda, M., Sztwiertnia, K., Kulczyk, M., et al. (2021). Structural and mechanical aspects of hypoeutectic Zn-Mg binary alloys for biodegradable vascular stent applications. Bioact. Mater. 6, 26–44. doi:10.1016/j.bioactmat.2020.07.004

PubMed Abstract | CrossRef Full Text | Google Scholar

Ralston, K. D., Birbilis, N., and Davies, C. H. J. (2010). Revealing the relationship between grain size and corrosion rate of metals. Scr. Mater. 63, 1201–1204. doi:10.1016/j.scriptamat.2010.08.035

CrossRef Full Text | Google Scholar

Reith, G., Schmitz-Greven, V., Hensel, K. O., Schneider, M. M., Tinschmann, T., Bouillon, B., et al. (2015). Metal implant removal: benefits and drawbacks--a patient survey. BMC Surgery 15, 96. doi:10.1186/s12893-015-0081-6

PubMed Abstract | CrossRef Full Text | Google Scholar

Ren, K., Zhang, K., Zhang, Y., Ju, J., Yan, K., Jiang, J., et al. (2021). Effect of ECAP temperature on formation of triple heterogeneous microstructure and mechanical properties of Zn–1Cu alloy. Mater. Sci. Eng. A 826, 141990. doi:10.1016/j.msea.2021.141990

CrossRef Full Text | Google Scholar

Shayesteh Moghaddam, N., Taheri Andani, M., Amerinatanzi, A., Haberland, C., Huff, S., Miller, M., et al. (2016). Metals for bone implants: safety, design, and efficacy. Biomanufacturing Rev. 1, 1. doi:10.1007/s40898-016-0001-2

CrossRef Full Text | Google Scholar

Shen, D., Li, Y., Shi, J., Zhang, T., Nie, J.-J., Chen, D., et al. (2025). Biodegradable zn-li-mn alloy to achieve optimal strength and ductility for bone implants. Acta Biomater. 199, 483–499. doi:10.1016/j.actbio.2025.04.056

PubMed Abstract | CrossRef Full Text | Google Scholar

Shi, Z.-Z., Yu, J., and Liu, X.-F. (2018). Microalloyed Zn-Mn alloys: from extremely brittle to extraordinarily ductile at room temperature. Mater. and Des. 144, 343–352. doi:10.1016/j.matdes.2018.02.049

CrossRef Full Text | Google Scholar

Valiev, R. Z., and Langdon, T. G. (2006). Principles of equal-channel angular pressing as a processing tool for grain refinement. Prog. Mater. Sci. 51, 881–981. doi:10.1016/j.pmatsci.2006.02.003

CrossRef Full Text | Google Scholar

Venezuela, J., and Dargusch, M. S. (2019). The influence of alloying and fabrication techniques on the mechanical properties, biodegradability and biocompatibility of zinc: a comprehensive review. Acta Biomater. 87, 1–40. doi:10.1016/j.actbio.2019.01.035

PubMed Abstract | CrossRef Full Text | Google Scholar

Wang, X., Ma, Y., Meng, B., and Wan, M. (2021). Effect of equal-channel angular pressing on microstructural evolution, mechanical property and biodegradability of an ultrafine-grained zinc alloy. Mater. Sci. Eng. A 824, 141857. doi:10.1016/j.msea.2021.141857

CrossRef Full Text | Google Scholar

Wang, M., Wang, K., Zhu, X., Yang, L., Shen, J., Lu, T., et al. (2024). In-vitro corrosion behavior and mechanical properties of biodegradable Zn alloys designed for gastrointestinal anastomosis. J. Mater. Res. Technol. 29, 4941–4953. doi:10.1016/j.jmrt.2024.02.191

CrossRef Full Text | Google Scholar

Wątroba, M., Bednarczyk, W., Kawałko, J., Lech, S., Wieczerzak, K., Langdon, T. G., et al. (2020). A novel high-strength Zn-3Ag-0.5Mg alloy processed by hot extrusion, cold rolling, or high-pressure torsion. Metallurgical Mater. Trans. A 51, 3335–3348. doi:10.1007/s11661-020-05797-y

CrossRef Full Text | Google Scholar

Windhagen, H., Radtke, K., Weizbauer, A., Diekmann, J., Noll, Y., Kreimeyer, U., et al. (2013). Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study. Biomed. Eng. OnLine 12, 62. doi:10.1186/1475-925X-12-62

PubMed Abstract | CrossRef Full Text | Google Scholar

Wu, D., Huang, T., and Liu, Z. (2022). Mechanical response of high purity Zn wires with different diameters. Mater. Lett. 324, 132635. doi:10.1016/j.matlet.2022.132635

CrossRef Full Text | Google Scholar

Yang, H., Jia, B., Zhang, Z., Qu, X., Li, G., Lin, W., et al. (2020). Alloying design of biodegradable zinc as promising bone implants for load-bearing applications. Nat. Commun. 11, 401. doi:10.1038/s41467-019-14153-7

PubMed Abstract | CrossRef Full Text | Google Scholar

Yang, H., Qu, X., Wang, M., Cheng, H., Jia, B., Nie, J., et al. (2021). Zn-0.4Li alloy shows great potential for the fixation and healing of bone fractures at load-bearing sites. Chem. Eng. J. 417, 129317. doi:10.1016/j.cej.2021.129317

CrossRef Full Text | Google Scholar

Yang, X., Du, P., Li, K., Bao, W., Xiang, T., Chen, J., et al. (2023). Optimization of mechanical properties and corrosion resistance of Zn-0.4Mn-0.8Li alloy using the hot rolling process. J. Mater. Sci. and Technol. 145, 136–147. doi:10.1016/j.jmst.2022.10.055

CrossRef Full Text | Google Scholar

Yang, X., Bao, W., Xiang, T., Cai, Z., Liu, X., and Xie, G. (2024). Biodegradable zn–mn–li alloy with a promising balance of mechanical property and corrosion resistance. J. Mater. Res. Technol. 30, 1852–1863. doi:10.1016/j.jmrt.2024.03.202

CrossRef Full Text | Google Scholar

Ye, L., Liu, H., Sun, C., Zhuo, X., Ju, J., Xue, F., et al. (2022). Achieving high strength, excellent ductility, and suitable biodegradability in a Zn-0.1Mg alloy using room-temperature ECAP. J. Alloys Compd. 926, 166906. doi:10.1016/j.jallcom.2022.166906

CrossRef Full Text | Google Scholar

Zhu, X., Yang, L., and Song, Z. (2024). The high strength and ductility mechanism of Zn-0.45Mn-0.8Li alloys with heterogeneous lamellar structure. Mater. Sci. Eng. A 909, 146853. doi:10.1016/j.msea.2024.146853

CrossRef Full Text | Google Scholar

Zhao, D., Huang, S., Lu, F., Wang, B., Yang, L., Qin, L., et al. (2016). Vascularized bone grafting fixed by biodegradable magnesium screw for treating osteonecrosis of the femoral head. Biomaterials 81, 84–92. doi:10.1016/j.biomaterials.2015.11.038

PubMed Abstract | CrossRef Full Text | Google Scholar

Zheng, Y. F., Gu, X. N., and Witte, F. (2014). Biodegradable metals. Mater. Sci. Eng. R Rep. 77, 1–34. doi:10.1016/j.mser.2014.01.001

CrossRef Full Text | Google Scholar

Zhuo, X., Zhao, L., Liu, H., Qiao, Y., Jiang, J., and Ma, A. (2023). A high-strength and high-ductility Zn–Ag alloy achieved through trace Mg addition and ECAP. Mater. Sci. Eng. A 881, 145381. doi:10.1016/j.msea.2023.145381

CrossRef Full Text | Google Scholar