We have developed a experimental equipment to examine the compressive creep behavior of ZA27 alloy in sand mold and permanent mold. The results showed that primary compressive creep strain and steady creep rate of the alloy increased with the increase in applied temperature and stress. The primary creep strain of the alloy in permanent mold is lower than in sand casting at lower temperature. Compressive creep strain of the alloy conformed to the empirical equation of 1nt = C -nlnσ + Q/RT. The stress exponent n of the alloy for sand casting and for permanent mold casting are 3.88 and 3.49 respectively and the activation energies are 85.44 kJ/mol and 81.02 kJ/mol respectively. The compressive creep strain of the alloy is governed by the lattice diffusion and dislocation limb of zinc. The compressive creep resistance of the alloy at whole testing temperuture and all applied stress in sand mold is higher than in permanent mold.
关键词
ZA27砂型铸造金属型铸造压蠕变
Keywords
ZA27 AlloyCasting in Sand MoldCasting in Metal MoldCompressive Creep