Heterogeneity of inelastic strain during creep of Carrara marble: Microscale strain measurement technique: MICROSCALE STRAIN MEASUREMENT TECHNIQUE
Heterogeneity of inelastic strain during creep of Carrara marble: Microscale strain measurement technique: MICROSCALE STRAIN MEASUREMENT TECHNIQUE
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卡拉拉大理石蠕变过程中非弹性应变的不均匀性：微尺度应变测量技术：微尺度应变测量技术
DOI：
10.1002/2016jb012970
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Evans, Brian
中科院分区：
文献类型：
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作者：
Quintanilla-Terminel, Alejandra;Evans, Brian
我们结合了劈裂圆柱体技术和微加工技术来观察卡拉拉大理石在高压瞬态蠕变过程中产生的应变不均匀性。使用间隔10 µm并包含嵌入式坐标系的定制设计的标记网格对样品进行图案化。这里描述的微尺度应变测量（MSSM）技术使我们能够分析局部应变分布与前所未有的细节在大区域。应变场的描述是计算应变的面积的函数。应变场可以被认为是均匀的尺度可以提供对发生的变形过程的洞察。在400-500°C下，当孪生产生较多时，我们观察到跨越几个晶粒的高度应变带。多晶粒带的一个可能的原因是需要减轻当孪晶撞击相邻晶粒时产生的应变不相容性。在600-700°C时，应变场仍相当不均匀，晶粒内和晶界附近的局部应变变化很大，但不存在多晶粒滑移带。变形集中在晶粒内的小得多的区域内以及沿着某些晶界。当变形条件允许额外的滑移系被激活时，多晶粒滑移带消失。在600°C下，当总应变从0.11变化到0.36时，不均匀性的空间尺度没有变化，但由总应变归一化的局部应变分布的标准差有所增加;因此，我们得出结论，微观结构在该应变区间内没有达到稳定状态。
We combined the split cylinder technique with microfabrication technology to observe strain heterogeneities that were produced during high‐pressure transient creep of Carrara marble. Samples were patterned with a custom‐designed grid of markers spaced 10 µm apart and containing an embedded coordinate system. The microscale strain measurement (MSSM) technique described here allowed us to analyze the local strain distribution with unprecedented detail over large regions. The description of the strain field is a function of the area over which strain is being computed. The scale at which the strain field can be considered homogeneous can provide insight into the deformation processes taking place. At 400–500°C, when twinning production is prolific, we observe highly strained bands that span several grains. One possible cause for the multigrain bands is the need to relieve strain incompatibilities that result when twins impinge on neighboring grains. At 600–700°C, the strain fields are still quite heterogeneous, and local strain varies substantially within grains and near grain boundaries, but the multigrain slip bands are not present. Deformation is concentrated in much smaller areas within grains and along some grain boundaries. The disappearance of the multigrain slip bands occurs when the deformation conditions allow additional slip systems to be activated. At 600°C, when the total strain is varied from 0.11 to 0.36, the spatial scale of the heterogeneity does not vary, but there are increases in the standard deviation of the distribution of local strains normalized by the total strain; thus, we conclude that the microstructure does not achieve a steady state in this strain interval.