On the correlation between hardness and tensile strength in particle reinforced metal matrix composites

The correlation between macrohardness and tensile strength of particle reinforced metal matrix composites was studied. Contrary to monolithic metals, a simple relationship between hardness and tensile strength was not found. The reinforcement fraction and matrix strength appear to play an important role in influencing the behavior of the composite under hardness and tensile loading conditions. The different loading modes of the tensile test compared to the hardness test, along with the local increase in particle concentration directly underneath the indenter during indentation, result in a significant overestimation of the tensile strength by the hardness test, especially when the matrix strength is relatively low.