25 year perspective Aspects of strain and strength measurement in miniaturised testing for engineering metals and ceramics
25 year perspective Aspects of strain and strength measurement in miniaturised testing for engineering metals and ceramics
复制标题
25 年展望工程金属和陶瓷小型化测试中应变和强度测量的各个方面
DOI：
10.1179/026708309x12584564052012
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发表时间：
2010
影响因子：
1.8
通讯作者：
Tanja Lube
中科院分区：
文献类型：
--
作者：
J. Lord;Bryan Roebuck;R. Morrell;Tanja Lube
微观领域的测试与许多技术问题有关，例如，通过去除小规模样本来评估已建工厂或新组件的性能；评估焊接结构的点对点差异；确定通常只有少量供应的昂贵的先进合金的特征；以及测试较小尺寸的组件。微型试件的使用需要注意底层微结构相对于试件整体尺寸的比例，并对小体积的应力和应变测量提出了挑战。这一主题涉及面很广，本文件的重点是讨论与强度和应变测量有关的问题，特别是使用基于数字图像相关的非接触式光学技术评估后者。因此，目前的文章集中在中等尺度(在0.5-5 mm范围内)的试验情况，其中试件与工程部件的尺寸相比较小，并且在必须考虑基础微结构的典型力学行为的范围内。计量问题通过具体的案例研究来解决，这些案例涉及：微单轴试验、小冲压试验、超细陶瓷强度试验和微压痕技术。特别注意使用微型测试以提供对这种测试区分材料行为的能力的可量化的置信度而产生的测量的不确定性。
Testing in the microregime is relevant to many technological issues, including, for example, evaluating the performance of established plant or new components through removal of small scale samples; assessing point to point variation in welded structures; characterising expensive advanced alloys that typically are only available in small quantities; and testing of subsized components. The use of miniature testpieces requires attention to the scale of the underlying microstructure relative to the overall testpiece dimensions, and presents challenges to the measurement of stress and strain in small volumes. The subject is extensive and the emphasis of the current paper is on a discussion of issues associated with the measurement of strength and strain, particularly with the latter assessed using non-contact optical techniques based on digital image correlation. The current article thus concentrates on the testing situation at the intermediate scale (in the range 0·5–5 mm) where testpieces are small compared with the size of engineering components and in the range where representative mechanical behaviour of the underlying microstructure must be considered. Metrology issues are addressed through specific case studies concerning; microuniaxial tests; small punch tests; subsized ceramic strength tests and the microindentation technique. Particular attention is paid to the uncertainties in measurement arising from the use of microscale tests to provide quantifiable levels of confidence in the ability of such tests to discriminate material behaviour.