Tribological behaviour of die tool materials used for die compaction in powder metallurgy

Abstract

A die wear model based on ‘wear work’ is put forward for use on die compaction tooling used in powder metallurgy. The model relies on integration of the frictional stress multiplied by velocity with respect to contact area and time. Two specially modified ASTM tribology tests, a pin-on-flat reciprocating test (one test per experimental point) and a continuous loop abrasion test (two tests per experimental point) were utilised to measure the wear on three candidate die materials. Mass loss and dimensional change of test specimens were used to quantify the wear. Based on the test results, a material property dependent constant was calculated for use in the new wear work model. Three different die materials were tested against two types of abrasive hard particles and two types of abrasive tapes. The wear resistance ranking of the three die materials is: WC » 10%V tool steel>CPM T15 tool steel.