Characterisation of plastic zones around crack-tips in pure single-crystal tungsten using electron backscatter diffraction
Characterisation of plastic zones around crack-tips in pure single-crystal tungsten using electron backscatter diffraction
复制标题
使用电子背散射衍射表征纯单晶钨裂纹尖端周围的塑性区
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Roberts
中科院分区：
文献类型：
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作者：
J. D. Murphy;A. Wilkinson;S. Roberts
用电子背散射衍射（EBSD）研究了钨中裂纹尖端塑性区的特征。采用电火花腐蚀法在纯钨单晶的~ 1 mm方形截面梁上制备了预裂纹。梁在不同的温度下加载到低于断裂韧性的应力强度因子范围。高分辨率EBSD图案记录在一个二维阵列附近的裂纹尖端的切片样品。基于互相关分析这些图案被用来确定晶格旋转与附近的裂纹的塑性变形。在观察平面中的晶体旋转被发现在其他平面中的旋转上占主导地位。对于以上的脆-韧性转变温度变形的所有试样，塑性区被发现从裂纹尖端沿着窄带沿着{110}平面上延伸。塑性区的大小及其相关的晶格旋转被确定为加载历史的函数。
Plastic zones around crack-tips in tungsten were characterised by electron backscatter diffraction (EBSD). Pre-cracks were made in ~1mm square cross section beams of pure single-crystal tungsten using a spark erosion method. The beams were loaded at different temperatures to a range of stress intensity factors below the fracture toughness. High resolution EBSD patterns were recorded in a two dimensional array in the vicinity of the crack-tip on sectioned samples. Cross-correlation based analysis of these patterns was used to determine lattice rotations associated with the plastic deformation near the cracks. Crystal rotations in the plane of observation were found to dominate over rotations in other planes. For all specimens deformed above the brittle-to-ductile transition temperature, plastic zones were found to extend from the crack tips on along narrow bands along {110} planes. The sizes of the plastic zones and their associated lattice rotations were determined as a function of loading history.