Densification Mechanisms Made During Creep Techniques Applied to the Hot Isostatic Pressing

Abstract

Hot isostatic compression involves the simultaneous application of pressure and elevated temperature to materials. The pressure applied, usually by a gas, is isostatic because it's developed in a suitable pressurized vessel by a fluid. Therefore in principle no alteration in component geometry occurs. Under these conditions of heat and pressure, internal pores or defects within a solid body or a powder compact collapse and weld up. Encapsulated powder and sintered components densify easily and faster than due to sintering alone. Therefore HIP is today used for a lot of applications, like upgrading castings (removing shrinkage pores in interdendritic space), densifying pre-sintered components, consolidation of powders and interfacial bonding. The paper presents some technical data regarding to densifying mechanism made by different creep techniques.