In order to develop high density powder metallurgy forming technology, a new concept combining high velocity compaction and warm compaction called warm high velocity compaction (WHVC) was presented. A new warm high velocity compaction forming equipment which adopts gravitational potential energy instead of hydraulic cylinder as hammer driver was designed. By means of the newly developed equipment, a preliminary study on warm high velocity compaction was performed. 316L stainless powder compacts with green density of 7.47 g/cm3 were obtained; the density is much higher than those prepared by conventional high velocity compaction. These results demonstrate that the newly designed equipment can basically meet the demand of warm high velocity compaction and the new forming method is superior to the conventional high velocity compaction. In addition, Densification mechanism of WHVC was also discussed.

Amorphous Fe79Ti16P5 alloy powders were synthesized from commercially available elemental powders by mechanical alloying. The microstructure, thermal stability and crystallization kinetic of as-milled powders were analyzed by XRD, SEM and DSC. Moreover, bulk ultrafine-grained materials were fabricated through spark plasma sintering of the amorphous powders. Results show that the amorphous powders exists two exothermal peaks during crystallization process. The effective activation energies for crystallization are obtained 109.14 kJ/mol and 205.97 kJ/mol for Ep1 and Ep2, respectively, by using the Kissinger method. The mechanical properties of the bulk materials are remarkably improved with the increase in the sintering temperatures. The ultimate compressive strength increases from 1282 MPa to 2015 MPa, but absence of ductility.