Testing of macroscopic hardness by acoustic response

Abstract

Static measurement of macroscopic hardness (hereinafter macrohardness) of metal materials by using indentation testing is accompanied by deformation in the vicinity of the indenter. Its indenting in a material, monitoring of consequent acoustic response during plastic deformation and interconnection with the records of acoustic emission (hereinafter AE) is the aim of this submitted paper. This non-destructive testing (NDT) method concentrates on the comparison of an acoustic event and the result of the hardness measurement of steels with different hardness values and for a specimen made from steel and tungsten carbide. The aforementioned measurements were conducted concurrently at two workplaces and resulted in very good conformance of records for hard materials. The result obtained confirms the possibility of carrying out correlation between the results of measuring hardness and those obtained from the hits at the acoustic emission testing.