Porosity Evaluation in High Performance Steels

摘要

Production of high density PM parts can expand the use of sintered components beyond its present limitations, as high density often is necessary for many heavy duty components suitable for PM such as transmissions and also safety parts. The purpose of this study is to investigate pore features and, in particular, the bigger pores, since these bigger pores are directly responsible for the mechanical properties (especially the dynamic ones) that a material shows. In this way, by means of image analysis techniques, the porosity study is conducted to study the effect of the 10% bigger pores and the effect of the whole pore system at densities 7.1 and 7.4 g/cm~3. So, pore area, maximum length and roundness are analysed for the two densities and a comparison of average values for those features is made in order to check out differences between densities and sintering temperatures (1120℃ and 1250℃). Results are correlated with mechanical properties.