Effect of hot pressing temperature and lubricant content on density and strength of iron powder metallurgy parts

The aim of the present paper is to investigate the effects of hot pressing treatment at different temperatures and the variation of lubricant contents on density, hardness and size/distribution of porosities in iron P/M parts. To produce various microstructural features, weight percentage of lubricants varied from 0.5 to 1.5 and pressing was performed at three temperatures of 25, 65 and 100 °C. The results showed a significant increase in density and strength for the samples produced by hot pressing in comparison with conventional pressing and sintering treatments. The highest density and hardness values were obtained for the minimum lubricant contents and maximum hot pressing temperature. Besides, microscopic observations proved that size, shape and distribution of porosities for samples pressed at 100 °C have been improved.