锰对铸态ZA27合金压缩蠕变的影响

Effect of Mn on kinetics of Compressive Creep in as Cast ZA27 Alloy

本文采用自制的试验装置研究了锰对铸态ZA2 7合金压缩蠕变行为的影响。结果表明 ,在所试验的温度为 2 0℃到 160℃和压应力为 5 0MPa到 13 7 5MPa的范围内 ,ZA2 7—Mn和ZA2 7合金的第一阶段压蠕变量和稳态蠕变速率随着温度和应力的增高而增大 ,但ZA2 7—Mn合金的第一阶段的蠕变量和稳态蠕变速率低于ZA2 7合金。两种合金的压蠕变均符合lnt=C—nlnσ +Q RT ,材料结构常数C不同合金压蠕变不同 ,ZA2 7—Mn合金的应力指数n和蠕变激活能Q分别为 3 89和 83 97KJmol- 1 ,而ZA2 7合金的应力指数和蠕变激活能分别为 3 46和81 0 9KJmol- 1 ,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 ,ZA2 7—Mn合金的压蠕变抗力高于ZA2

The effect of Mn on the kinetics of compressive creep behavior in as cast ZA27 alloy was investigated at room and high temperatures in the range 20℃～160℃ and under different compressive stress in the range 50MPa～137.5MPa with special apparatus.The results obtained showed that the primary compressive creep strains and steady creep rates of ZA27—Mn and ZA27 alloys increased with the temperature and stress used,however,the primary compressive creep strain and steady creep rate of the ZA27—Mn alloy were lower than that of the ZA27 alloy.The compressive creep in both ZA27—Mn and ZA27 alloy obeyed an empirical equation lnt=C—nlnσ+Q/RT,and the exponent stress n 3.89,for ZA27—Mn alloy and 81.09KJmol -1 for ZA27 alloy.Different material structural constant C was associated with different compressive creep in this alloy.The compressive creep in the alloy was controlled by te lattice diffusion of zinc and dislocation limb.The resistance to compressive creep of ZA27—Mn alloy was higher than that of ZA27 alloy in all range of temperature and stress used.