Effect of Ca content and rheo-squeeze casting parameters on microstructure and mechanical properties of AZ91−1Ce−xCa alloys  

Ca含量和流变挤压铸造工艺参数对AZ91−1Ce−xCa合金显微组织和力学性能的影响

作　　者：Ran XIAO Wen-cai LIU Guo-hua WU Liang ZHANG Bao-liang LIU Wen-jiang DING 肖然;刘文才;吴国华;张亮;刘保良;丁文江(上海交通大学材料科学与工程学院,轻合金精密成型国家工程中心和金属基复合材料国家重点实验室,上海200240)

机构地区：[1]National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composite,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第6期1572-1586,共15页中国有色金属学报（英文版）

基　　金：financial supports from National Natural Science Foundation of China(Nos.51775334,51771115,U2037601);Research Program of Joint Research Center of Advanced Spaceflight Technologies,China(No.USCAST2020-14)。

摘　　要：The microstructure,mechanical properties and flame resistance behavior of the AZ91−1Ce alloys with different Ca additions were firstly investigated.Then,the effect of processing parameters,including applied pressures and rotation speeds,on the microstructure and mechanical properties of the rheo-squeeze casting AZ91−1Ce−2Ca alloy was studied.The results indicate that with the increase of Ca content,the microstructure is refined and the flame resistance of the AZ91−1Ce−xCa alloys increases.But when the Ca content exceeds 1 wt.%,with the Ca content increasing,the mechanical properties of the AZ91−1Ce−xCa alloys reduce rapidly.For rheo-squeeze casting process,the increase of applied pressure and rotation speed can both bring about significant refinement in the microstructure of the AZ91−1Ce−2Ca alloy and reduction of the porosity,so the mechanical properties increase.Compared to conventional casting,the AZ91−1Ce alloy with the addition of 2 wt.%Ca by rheo-squeeze casting not only guarantees the oxidation resistance(801℃),but also improves mechanical properties.首先,研究不同Ca含量AZ91−1Ce合金的显微组织、力学性能和阻燃性能,优化出最佳Ca含量。然后,系统研究流变挤压铸造工艺参数(包括压力和转速)对AZ91−1Ce−2Ca合金显微组织和力学性能的影响。结果表明,随着Ca含量的增加,AZ91−1Ce−xCa合金的显微组织细化,阻燃性能提高。但当Ca含量超过1%(质量分数)时,随着Ca含量的增加,AZ91−1Ce−xCa合金的力学性能迅速降低。在流变挤压铸造工艺中,压力和转速增加使AZ91−1Ce−2Ca合金的组织明显细化,气孔率降低,力学性能提高。与常规铸造相比,添加2%Ca(质量分数)的AZ91−1Ce合金经流变挤压铸造成形后,不仅保证合金的抗氧化性(801℃),而且提高其力学性能。

关 键 词：CA AZ91−1Ce alloy oxidation resistance rheo-squeeze casting 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG24[金属学及工艺—金属材料]