Ca和Sr对AE42合金蠕变性能的影响  

Effects of Ca and Sr additions on creep resistance of AE42 magnesium alloy

作　　者：薛山[1] 孙扬善[1] 丁绍松[1] 白琴[1] 陶立[1] 薛烽[1] 

机构地区：[1]东南大学材料科学与工程系,南京210096

出　　处：《东南大学学报（自然科学版）》2005年第2期261-265,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家高技术研究发展计划 (863计划 )资助项目(2001AA331030 01)

摘　　要：研究了碱土元素Ca和Sr对AE42耐热镁合金蠕变性能的影响.试验结果表明,铸态AE42合金中的显微组织由α Mg基体、针状的Al11La3 相和少量粒状的Al2La组成.在 175℃, 70MPa的蠕变条件下,针状的Al11La3 相分解成为Al2La和Mg17Al12,导致AE42合金蠕变性能的急剧下降.在AE42中加入Ca和Sr后,针状的Al11La3 逐渐被Al2Ca相和Al4Sr金属间化合物以及少量Al2La取代,分布在晶界的Al2Ca相和Al4Sr相具有很高的热稳定性,使合金的蠕变性能得到了极大的提高.The effects of alkaline elements Ca and Sr additions on creep resistance of heat resistant magnesium alloy AE42 have been studied. The results show that the as-cast microstructure of AE42 is composed of α-Mg matrix, acicular Al11La3 phase and small amount of particulate Al2La phase. The poor creep resistance of AE42 at 175°C and 70 MPa is due to the acicular Al11La3 phase decomposes to Al2La and Mg17Al12. The acicular Al11La3 phases is gradually replaced by Al2Ca and Al4Sr intermetallic compound and small amount of Al2La with Ca and Sr addition into AE42. The Al2Ca and Al4Sr intermetallic phases distributing at grain boundaries have very high thermal stability, thus resulting in significant improvement of creep resistance.

关 键 词：蠕变性能 Sr Ca 金属间化合物 耐热镁合金 试验结果 显微组织 热稳定性 针状 相分解 极大的 基体 铸态 r相 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TB852.1[金属学及工艺—金属材料]