Oliver&Pharr压入硬度与材料单轴强度关系的研究

Research of Relationship between Oliver&Pharr Hardness and Uniaxial Strengths

通过量纲分析和有限元数值计算,系统研究了Oliver&Pharr压入硬度与材料单轴强度间的关系,结果表明σE,y+σE,b与Oliver&Pharr压入硬度H以及压入比功We/W之间存在近似的函数关系,即材料屈服强度和拉伸强度之和与Oliver&Pharr压入硬度之比近似为压入弹性功与压入总功之比的函数。利用该关系,材料的屈服强度和拉伸强度之和可以由一次压入测试结果来获得,这使得利用压入技术对材料强度水平进行直接比较成为可能,因而克服了过去仅仅基于压入硬度值,只能对材料强度水平做相对比较的缺点和不足。

Dimensional and finite element analysis were employed to analyze the difference between Oliver＆Pharr hardness and uniaxial strengths. Results revealed the existence of a function dependence of the sum of the engineering yield strength and tensile strength on indentation hardness and the ratio of reversible elastic work to total work obtained from an indentation test. The relationship can be used to deduce the sum of the engineering yield strength and tensile strength of a material from the results of an indentation test. This suggests that it is possible to compare the strength levels of two materials directly based on indentation technique while comparison of hardnesses alone may not be sufficient to reflect the real difference in the relative strength levels of two materials.