摘要
采用自制的试验装置研究了ZA2 7合金在砂型和金属型铸造条件下的压蠕变行为。结果表明 ,合金第一阶段的压蠕变量和稳态蠕变速率随着温度和应力的增高而增大 ,在较低温度时 ,金属型铸造合金第一阶段的蠕变量低于砂型铸造合金的。合金的压蠕变符合经验公式ln(t/s) =C -nln(σ/MPa) +Q/(RT) ,砂型铸造合金的应力指数n和蠕变激活能Q分别为 3.88和 85 .44kJ/mol,而金属型铸造合金的应力指数和蠕变激活能分别为 3.49和 81.0 2kJ/mol。合金的压蠕变由锌的点阵自扩散和位错的攀移控制 ,在整个试验温度和应力范围内 ,砂型铸造合金的压蠕变抗力高于金属型铸造合金的。
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.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2003年第1期19-21,共3页
Special Casting & Nonferrous Alloys
关键词
ZA27合金
砂型铸造
金属型铸造
压蠕变
ZA27 Alloy, Casting in Sand Mold, Casting in Metal Mold, Compressive Creep
