采用数字散斑相关技术计算了被测表面硬度压痕周围的塑性变形场特征,结合不同显微硬度测试方法的结果及有限元模拟结果,系统讨论了压痕尺寸效应问题.结果表明:在不同测试条件下,被测表面压痕周围的变形表现出两种状态,并且与载荷有关,使表面变形方向改变的载荷与产生压痕尺寸效应时的载荷是比较接近的;说明现有压痕计算在建模时不论载荷大小,而采用一种模型是不合理的,即当压头压入材料的深度不同时应该采用不同的模型进行分析计算.

The indentation size effect is discussed in detail through calculating surface plastic deformation around indentation by digital speckle correlation method (DSCM),testing hardness by different micro hardness-testing devices and finite element analysis(FEA).The results show that under different test conditions,surface deformation around the indentation correlates to the load and shows two states,and loads of changing surface deformation direction and producing indentation size effect are close.This indicates that the present indentatin calculation only using one model regardless the loads is unreasonable.So different models should be adopted when the indentation depth is different.