Characterization of Fracture Behavior in Small Punch Test by Combined Recrystallization-Etch Method and Rigid Plastic Analysis

TLDR: In this article, the deformation process of the small punch test and its use to characterize the fracture properties of materials were investigated. But the results of biaxial equivalent fracture strain can be related almost linearly to fracture toughness (JIc) for elastic-plastic behavior.

Abstract: The purpose of this investigation is to understand the deformation process of the small punch test and to use it to characterize the fracture properties of materials. By comparisons between recrystallization-etch results and perfect-rigid plastic analysis, the deformation process of the small punch test has been clearly divided into three regions. Equivalent fracture strain under biaxial stress state has been obtained from 10 by 10 by 0.5 mm thin sheet samples using both a recrystallization-etch technique and a semi-analytical method to characterize the fracture property of the material. The results of biaxial equivalent fracture strain can be related almost linearly to fracture toughness (JIc) for elastic-plastic behavior.