The heat treatment of powder-metal (PM) parts presents a number of unique challenges, influenced primarily by material and density considerations. Common post-sintering processes include sinter hardening and conventional post-sintering heat-treatment operations. Let’s learn more.
The process of sinter hardening is an alternative to conventional post-sintering hardening or case hardening and quenching, which takes place in a separate heat-treatment furnace. Sinter hardening is conducted inside the sintering furnace itself and involves rapid cooling after sintering to transform the microstructure to martensite. Cooling speeds vary by alloy, but rates in the range of 1-2°C/sec. (2-4°F/sec.) from 760-205°C (1400-400°F) are typical. Carbon control of the furnace atmosphere is particularly important to achieving desired mechanical properties.