12579Southeast University, Nanjing, China.
Institute of Biomedical Devices (Suzhou), Suzhou, China.
J Biomater Appl. 2022 Nov;37(5):891-902. doi: 10.1177/08853282221123934. Epub 2022 Aug 27.
In this study, Zn-xCu (-0.1 Mg) wires with a diameter of 0.3 mm were obtained by hot extrusion and cold drawing. The microstructures, mechanical properties, and degradation behaviour were investigated to evaluate their feasibility as biodegradable metals. During the drawing process of the Zn-xCu alloys, many granular CuZn phases were dynamically precipitated, and the grains were significantly refined, along with a significant work softening with the tensile strength decreasing and the elongation increasing (from 161 MPa to 92 MPa and 22%-103% for Zn-0.2Cu). With the increase of Cu additions, the phenomenon of work softening was more intense and there was an opposite trend in the strength changes between the as-extruded rods (increase) and as-drawn wires (decrease). With 0.1 wt.% Mg added, the stable rod-like MgZn phase was formed in as-extruded Zn-xCu-0.1 Mg rods, which obviously improved the strength, and inhibited the dynamic precipitation of granular CuZn phase and work softening phenomenon in the drawing process (from 332 MPa to 313 MPa and 11%-46% for Zn-0.2Cu-0.1 Mg). In addition, due to the micro-galvanic effect induced by the precipitates, alloying accelerated the degradation of Zn alloy wires, especially Zn-1Cu-0.1 Mg, which was related to the shape, distribution, and potential of the phases.
本研究通过热挤压和冷拉拔获得了直径为 0.3mm 的 Zn-xCu（-0.1Mg）线材。研究了其微观结构、力学性能和降解行为，以评估其作为可生物降解金属的可行性。在 Zn-xCu 合金的拉拔过程中，许多颗粒状的 CuZn 相动态析出，晶粒明显细化，同时伴随着显著的加工软化，拉伸强度降低，伸长率增加（Zn-0.2Cu 从 161MPa 降至 92MPa，增加了 22%至 103%）。随着 Cu 含量的增加，加工软化现象更加明显，挤压棒（增加）和拉拔丝（减少）的强度变化趋势相反。添加 0.1wt.%Mg 后，在挤压态的 Zn-xCu-0.1Mg 棒中形成了稳定的棒状 MgZn 相，明显提高了强度，并抑制了拉拔过程中颗粒状 CuZn 相的动态析出和加工软化现象（Zn-0.2Cu 从 332MPa 降至 313MPa，降低了 11%至 46%）。此外，由于析出物的微电偶效应，合金加速了 Zn 合金线材的降解，尤其是 Zn-1Cu-0.1Mg，这与相的形状、分布和电位有关。
