Effect of intermediate sintering temperature on the properties of domestic air conditioner components produced by double pressing

Abstract

In the pressing of parts of high density the factor of degassing of the charge being pressed acquires special significance. In the designing of die sets for pressing parts of large size and complex configuration particular attention should be given to choice, with allowance for the properties of the charge, of optimum clearances between moving forming elements. It may be desirable to incorporate in the design of die sets auxiliary elements forming additional drain clearance lines. The process of pore formation in sintered materials commences during pressing, continues during intermediate sintering as a consequence of evaporation of plasticizer and degassing of compacts, and comes to an end at a high temperature. The rate of heating of compacts can affect the density, chemical composition, and strength properties of sintered parts. For ZhGr0.8 and ZhGr0.65D2N1 rollers heated for 40 min under isothermal conditions, the optimum intermediate sintering temperature may be taken to be 900 ± 20‡C.