LeoMet
CPM 3V
Faulty P/M steel.
Steel powders are compacted under high temp (1100~ 1200?) ato get rid of voids between particles in order to make a "solid" steel. Sometimes, voids are not completely removed and are left inside the steel. After machining, these voids open up to free surface. In this case, the voids open up on functional edge of a tooling serve as stress riser / crack initiator and cause the punch to fail prematurely.
CPM 3V
Faulty P/M steel.
Steel powders are compacted under high temp (1100~ 1200?) ato get rid of voids between particles in order to make a "solid" steel. Sometimes, voids are not completely removed and are left inside the steel. After machining, these voids open up to free surface. In this case, the voids open up on functional edge of a tooling serve as stress riser / crack initiator and cause the punch to fail prematurely.