摘要
采用自制的实验装置研究了铸态Mg-4Al-1RE-1Ca-0.2Sr(AECJ411002)合金在温度为125～175℃和压力为88～112MPa范围内的压蠕变行为。结果表明,随温度和应力升高,合金的压蠕变量增大,稳态蠕变速率的对数分别与应力的对数和温度的倒数呈较好的线性关系,稳态蠕变速率符合半经验公式。在不同的温度下,应力指数n相近,平均值为6.19;不同的应力下,表观激活能Qa相差不大,平均值为39.05kJ/mol,材料的结构常数A为4.18×10-14,稳态蠕变速率由位错攀移控制。AECJ411002合金中沿着晶界分布的Al2Ca相和Al4Sr相具有很高的热稳定性,能提高合金的抗蠕变性能。
The compressive creep behavior of Mg-AI-RE-Ca-Sr（AECJ411002） alloy was investigated at temperatures in the range of 125～175℃and different compressive stress in the range of 88 ～112 MPa with special apparatus. The results show that the creep increases with increasing temperature and compressive stress. There is linear logarithmic relationship between the steady creep rate and all the temperature and stress used. The steady creep rate obeys an empirical equation. The stress exponents are similar at different temperatures and the appearance activation energies are not greatly different under different stresses. The average values are 6.19 and 39.05 kJ/mol respectively. Material constant A is 4.18 ×10^-14 The steady creep rate is controlled by a dislocation climb. The creep resistances enhance because the Al2Ca and Al4Sr distributing at grain boundaries have high thermal stability.
出处
《铸造技术》
CAS
北大核心
2009年第11期1452-1455,共4页
Foundry Technology
