Insight into indentation-induced plastic flow in austenitic stainless steel
Insight into indentation-induced plastic flow in austenitic stainless steel
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DOI：
10.1007/s10853-020-04646-y
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发表时间：
2020-04
影响因子：
4.5
通讯作者：
Wenzhen Xia;G. Dehm;S. Brinckmann
中科院分区：
文献类型：
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作者：
Wenzhen Xia;G. Dehm;S. Brinckmann
在过去的几十年里，人们通过实验和模拟对压痕诱导的塑性和粗糙度进行了深入的研究。然而，位错流如何导致堆积形成的确切机制仍然不完全清楚，尽管这是导致低载荷下摩擦学接触表面粗糙的初始步骤之一。在本工作中，奥氏体不锈钢[(面心立方(Fcc)相])中的-、和-晶取向在不同的载荷下被压痕。通过扫描电子方法和滑移面分析，我们揭示了：(1)滑移台阶如何反映堆积形成的变化；(2)滑移面倾角如何决定位错流；(3)滑移面相互作用如何导致压痕过程中最终的堆积形状。我们发现，在滑移面和表面之间的过渡角处，流动方向由正向流向侧向流转变。我们使用大位移有限元模拟来验证在这个转折角的分辨剪应力的反演。我们对位错介导的面心立方金属压痕的塑性演化提供了见解，并将这些信息潜在地应用于压痕模拟和理解未来摩擦学中划痕的初始阶段。
The indentation-induced plasticity and roughness have been investigated intensively by experiments and simulations during the last decades. However, the precise mechanisms of how dislocation flow leads to pile-up formation are still not completely understood, although this is one of the initial steps causing surface roughening in tribological contacts at low loads. In this work,-,- and-grain orientations in an austenite stainless steel [(face-centered cubic (FCC) phase]) are indented with varying load forces. By using scanning electron-based methods and slip plane analysis, we reveal: (1) how slip-steps show the change of pile-up formation, (2) how the slip-plane inclination determines the dislocation flow and (3) how slip-plane interactions result in the final pile-up shape during indentation. We find that the flow direction transforms from the forward flow to the sideway at a transition angle ofbetween the slip-plane and the surface. We use large displacement finite element method simulations to validate an inversion of the resolved shear stress at this transition angle. We provide insights into the evolution of plasticity in dislocation-mediated FCC metal indentations, with the potential application of this information for indentation simulations and for understanding the initial stage of scratching during tribology in the future.