Wang Wenhui, Blawert Carsten, Zan Rui, Sun Yu, Peng Hongzhou, Ni Jiahua, Han Pei, Suo Tao, Song Yang, Zhang Shaoxiang, Zheludkevich Mikhail L, Zhang Xiaonong
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Magnesium Innovation Centre (MagIC), Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, 21502, Germany.
Bioact Mater. 2021 Apr 30;6(12):4333-4341. doi: 10.1016/j.bioactmat.2021.04.020. eCollection 2021 Dec.
Lean alloy (low alloyed) is beneficial for long-term sustainable development of metal materials. Creating a nanocrystalline microstructure is a desirable approach to improve biodegradability and mechanical properties of lean biomedical Mg alloy, but it is nearly impossible to realize. In the present study, the bulk nanocrystalline Mg alloy (average grain size: ~70 nm) was successfully obtained by hot rolling process of a lean Mg-2wt.%Zn (Z2) alloy and both high strength ((223 MPa (YS) and 260 MPa (UTS)) and good corrosion resistance (corrosion rate in vivo: 0.2 mm/year) could be achieved. The microstructure evolution during the rolling process was analyzed and discussed. Several factors including large strain, fine grains, strong basal texture, high temperature and Zn segregation conjointly provided the possibility for the activation of pyramidal <c+a> slip to produce nanocrystals. This finding could provide a new development direction and field of application for lean biomedical Mg alloys.
贫合金（低合金化）有利于金属材料的长期可持续发展。创建纳米晶微观结构是改善贫生物医用镁合金生物降解性和力学性能的理想方法，但几乎无法实现。在本研究中，通过对贫Mg-2wt.%Zn（Z2）合金进行热轧工艺，成功获得了块状纳米晶镁合金（平均晶粒尺寸：约70nm），并实现了高强度（屈服强度223MPa和抗拉强度260MPa）和良好的耐腐蚀性（体内腐蚀速率：0.2mm/年）。分析并讨论了轧制过程中的微观结构演变。大应变、细晶粒、强基面织构、高温和锌偏析等多种因素共同为激活< c + a >锥面滑移以产生纳米晶体提供了可能性。这一发现可为贫生物医用镁合金提供新的发展方向和应用领域。
