Properties of High-Strength PM Materials Obtained by Different Compaction Methods in Combination with High Temperature Sintering
PM²TEC 2002, in Orlando, USA. Authors: Ingrid Hauer, Mats Larsson, Ulf Engström. New applications for PM steels are continuously introduced on the market. Many of these new applications utilize the unique possibilities of PM to achieve high strength in combination with close dimensional tolerances and a minimum of manufacturing operations. Materials like Astaloy CrM and Astaloy Mo +2%Ni are all aimed at applications combining high strength with close dimensional tolerances. These materials reach tensile strength levels in the range of 650 MPa to 1000 MPa after conventional compaction at room temperature and sintering in belt furnaces at 1120°C (2050°F). By applying high temperature sintering i.e. sintering at temperatures > 1200°C (2200°F), these strength levels can be further increased. By combining high temperature sintering with warm compaction or high velocity compaction (HVC) PM materials with even higher strength levels can be obtained. This paper describes the influence of sintering temperature on static and dynamic properties for conventionally pressed, warm compacted and high velocity compacted powder mixes based on Astaloy CrM and Astaloy Mo +2%Ni.