Orientation informed nanoindentation of α-titanium: Indentation pileup in hexagonal metals deforming by prismatic slip
Orientation informed nanoindentation of α-titanium: Indentation pileup in hexagonal metals deforming by prismatic slip
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DOI：
10.1557/jmr.2011.334
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发表时间：
2012-01-01
影响因子：
2.7
通讯作者：
Raabe, Dierk
中科院分区：
文献类型：
--
作者：
Zambaldi, Claudio;Yang, Yiyi;Raabe, Dierk
本研究报告的各向异性压痕响应的α-钛。用电子背散射衍射对粗晶钛进行了表征。球锥形纳米压痕进行了一些不同的结晶取向。晶粒尺寸远大于压痕的尺寸，以确保准单晶压痕。六边形c轴被确定为最难的方向。用原子力显微镜测量了几个压痕的表面形貌。根据Zambaldi和Raabe（Acta Mater. 58（9），3516-3530）揭示了α-钛在轴对称压痕过程中的取向依赖性堆积行为。相应的晶体塑性有限元（CPFE）模拟预测堆积模式具有良好的精度。CPFE模型的本构参数识别的非线性优化过程中，可重复收敛到容易激活的棱柱滑移系统。计算的临界分辨剪切应力分别为150 +/- 4、349 +/- 10和1107 +/- 39 MPa，用于棱柱和基底< a >滑移以及金字塔< c + a >-滑移。
This study reports on the anisotropic indentation response of alpha-titanium. Coarse-grained titanium was characterized by electron backscatter diffraction. Sphero-conical nanoindentation was performed for a number of different crystallographic orientations. The grain size was much larger than the size of the indents to ensure quasi-single-crystal indentation. The hexagonal c-axis was determined to be the hardest direction. Surface topographies of several indents were measured by atomic force microscopy. Analysis of the indent surfaces, following Zambaldi and Raabe (Acta Mater. 58(9), 3516-3530), revealed the orientation-dependent pileup behavior of alpha-titanium during axisymmetric indentation. Corresponding crystal plasticity finite element (CPFE) simulations predicted the pileup patterns with good accuracy. The constitutive parameters of the CPFE model were identified by a nonlinear optimization procedure, and reproducibly converged toward easy activation of prismatic glide systems. The calculated critical resolved shear stresses were 150 +/- 4, 349 +/- 10, and 1107 +/- 39 MPa for prismatic and basal < a >-glide and pyramidal < c + a >-glide, respectively.