The effects of alloying with Cu and Mn and thermal treatments on the mechanical instability of Zn-0.05Mg alloy
The effects of alloying with Cu and Mn and thermal treatments on the mechanical instability of Zn-0.05Mg alloy
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DOI：
10.1016/j.msea.2019.138529
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发表时间：
2020-01-07
期刊：
影响因子：
6.4
通讯作者：
Drelich, Jaroslaw W.
中科院分区：
文献类型：
--
作者：
Ardakani, Morteza S.;Mostaed, Ehsan;Drelich, Jaroslaw W.
自然时效对锌合金力学性能的不利影响限制了其作为生物可吸收医用植入物的应用。研究了Zn-0.05Mg合金的时效处理以及添加0.5Cu和0.1Mn（质量百分比）对合金组织和拉伸性能的影响。对合金进行了冷轧、J时效和退火处理，旨在研究析出相和晶粒尺寸对合金力学性能及其稳定性的影响。TEM分析表明，在超细晶Zn-0.05Mg合金中，自然时效是由于纳米级Mg 2 Zn 11析出相的形成。在自然时效90天后，Zn-0.05Mg合金的屈服强度和极限抗拉强度分别从197 +/-4MPa和227 +/-5MPa增加到0.233 +/-8MPa和305 +/-7MPa，而伸长率从34 +/-3%急剧降低到3 +/-1%。添加0.1Mn或0.5Cu的第三种元素可延缓合金的自然时效，并与Zn固溶体中的Mg相互作用，阻止Mg 2 Zn 11析出相的形成。Cu和Mn元素的加入提高了合金的强度、塑性和室温力学稳定性。Zn-0.1Mn-0.05Mg测得的拉伸强度和伸长率分别为274 +/-5MPa和41 +/-1%，Zn-0.5Cu-0.05Mg测得的拉伸强度和伸长率分别为312 +/-2MPa和44 +/-2%。高温退火使合金晶粒尺寸增大，第二相溶解，影响合金的变形机制。
The detrimental effect of natural aging on mechanical properties of zinc alloys restricts their application as bioresorbable medical implants. In this study, aging of Zn-0.05Mg alloy and the effect of 0.5 Cu and 0.1 Mn (in weight percent) addition on the microstructure and tensile properties were studied. The alloys were cold rolled, J aged and annealed; aiming to investigate the effects of precipitates and grain size on the mechanical properties and their stability. TEM analysis revealed that in ultrafine-grained binary Zn-0.05Mg alloy, the natural aging occurred due to the formation of nano-sized Mg2Zn11 precipitates. After 90 days of natural aging, the yield - strength and ultimate tensile strength of Zn-0.05Mg alloy increased from 197 +/- 4 MPa and 227 +/- 5 MPa to .233 +/- 8 MPa and 305 +/- 7 MPa, respectively, while the elongation was drastically reduced from 34 +/- 3% to 3 +/- 1%. This natural aging was retarded by adding the third element at either 0.1Mn or 0.5Cu quantities, which interacted with Mg in Zn solid solution and impeded the formation of Mg2Zn11 precipitates. The addition of Cu and Mn elements increased alloy's strength, ductility, and its mechanical stability at a room temperature. The measured tensile strength and elongation were 274 +/- 5 MPa and 41 +/- 1% for Zn-0.1Mn-0.05Mg and 312 +/- 2 MPa and 44 +/- 2% for Zn-0.5Cu-0.05Mg, respectively. Annealing the alloys at elevated temperatures caused increase in both grain size and dissolution of secondary phases, and both affected alloy deformation mechanisms.