ANALYSIS OF SHOT-PEENING BEHAVIOR OF SINTERED METAL ON FATIGUE LIFETIME
Keywords:
Sintered metal, shot peening, fatigue, surfaceAbstract
The shot peening process is recommended for surface cleaning at the end of the component part production process to improve the mechanical properties of cast ferrous and non-ferrous metals. It is one of the mechanical surface treatments. At the surface, the compressive residual stress and the dislocation density (in the work hardening state) for cast metal induced by the shot peen-ing process improves the fatigue lifetime performance. For sintered metals, although the compressive residual stress and work hardening state can be generated by the shot peening process, the porosities in the sintered metal have more of an effect on the fatigue lifetime. Therefore, an increase of the surface roughness and the non-existent surface case depth can reduce the fa-tigue lifetime of sintered metal. In this work, the effect of shot peening on the near surface properties and microstructure were investigated. It was demon-strated that the high roughness and the non-uniform hardness values in the lower depth from the surface had more effect than the compressive residual stress and work hardening state. Unfortunately, the shot peening process in-significantly increases the fatigue performance of sintered metal.
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