Microstructural evolution during dry wear test in magnesium and Mg-Y alloy
Microstructural evolution during dry wear test in magnesium and Mg-Y alloy
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DOI：
10.1016/j.msea.2012.10.034
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发表时间：
2013-01-20
期刊：
影响因子：
6.4
通讯作者：
Mukai, Toshiji
中科院分区：
文献类型：
--
作者：
Somekawa, Hidetoshi;Maeda, Shunsuke;Mukai, Toshiji
采用销-盘式摩擦磨损试验机研究了纯镁和镁-Y合金的摩擦磨损性能。镁Y合金的摩擦磨损性能优于纯镁合金。在所有条件下，其磨损机制均为磨粒磨损。用透射电子显微镜和背散射电子衍射仪观察了近表面区的变形组织演变。并通过有限元分析(FEA)对应力应变状态进行了评估。两种合金的变形组织都由{10-12}孪晶组成，有限元分析结果表明，在试验开始时就已经发生了塑性变形。随着外加载荷的增加，镁Y合金中形成了小角度晶界。另一方面，随着磨损试验的进行，观察到了动态再结晶对纯镁的细化作用。不同的显微组织是由于磨损试验中表面温度的不同造成的，纯镁和镁Y合金的表面温度分别约为393K和363K。细晶合金的高温升导致了晶界滑移，即材料软化，从而导致摩擦磨损性能下降。结果表明，提高动态再结晶温度是提高摩擦磨损性能的方法之一。(C)2012爱思唯尔B.V.保留所有权利。
The friction and wear properties of pure magnesium and the Mg-Y alloy were investigated using the pin-on-disk configuration. The friction and wear resistance of the Mg-Y alloy was superior to those of pure magnesium. The wear mechanism was abrasion under all the conditions. The deformed microstructural evolutions near the surface region were observed by transmission electron microscopy and electron backscatter diffraction. The stress and strain states were also evaluated by finite element analysis (FEA). The deformed microstructures of both alloys consisted of the {10-12} twinning formation and the FEA results showed the occurrence of plastic deformation even at the beginning of the test. The formation of low angle grain boundaries was also confirmed with an increase in the applied load in the Mg-Y alloy. On the other hand, grain refinement due to dynamic recrystallization was observed in pure magnesium as the wear test progressed. The different microstructures resulted from difference in the surface temperature during the wear test, which was estimated to be around 393 K and 363 K for pure magnesium and the Mg-Y alloy, respectively. The high increment temperature in the fine-grained alloys brought about the occurrence of grain boundary sliding, i.e., material softening, which led to a decrease in the friction and wear properties. The present results indicated that one of the methods for enhancing the friction and wear properties is to increase the dynamic reaystallization temperature. (C) 2012 Elsevier B.V. All rights reserved.