浇注温度对近液相线挤压铸造AZ91D镁合金组织及性能的影响  

Effects of Pouring Temperature on Microstructure and Mechanical Property of Near-liquidus Squeeze Casting AZ91D Alloy

作　　者：赵春芳[1,2] 马光全 颜泽华[3] 胡茂良 吉泽升[1,2] Zhao Chunfang;Ma Guangquan;Yan Zehua;Hu Maoliang;Ji Zesheng(School of Mechanical and Electrical Engineering,Lishui Vovational and Technical College,Lishui 323000;School of Materials Science and Chemical Engineering,Harbin University of Science and Technology,Harbin 150080;Rongcheng Campus,Harbin University of Science and Technology,Rongcheng 264300)

机构地区：[1]丽水职业技术学院机械工程学院,丽水323000 [2]哈尔滨理工大学材料科学与化学工程学院,哈尔滨150080 [3]哈尔滨理工大学荣成学院,荣城264300

出　　处：《特种铸造及有色合金》2024年第1期105-110,共6页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51574100)。

摘　　要：以汽车差速器支架为对象,研究了不同浇注温度下近液相线挤压铸造AZ91D镁合金的组织及力学性能。结果表明,浇注温度由595℃升至665℃时,合金内部球状晶逐渐长大成蔷薇状晶,平均晶粒尺寸由21.02μm增大到58.13μm。第二相β-Mg17Al12的含量从18.55%提高到49.72%,且分布均匀性逐渐降低。浇注温度较低(595℃和605℃)时,合金拉伸断口存在大量韧窝和小面积的解理平面;随着浇注温度提高,断口的韧窝数量、解理台阶逐渐减少。浇注温度为605℃时,合金的抗拉强度为229.2 MPa,伸长率为3.16%,均达到了最大值。Taking the automobile differential supportor as object, the microstructure and mechanical properties of AZ91D alloy were investigated under different near-liquidus squeeze casting temperatures. The results indicate that when the pouring temperature is increased from 595 ℃ to 665 ℃, the spherical crystal in the alloy is gradually transformed into a rosette-like crystal, and the average grain size is increased from 21. 02 μm to 58. 13 μm. The content of the second phase β-Mg17Al12 is increased from 18. 55% to 49. 72%, and its uniformity is gradually weakened. When the pouring temperature is low(595 ℃ and 605 ℃), there exist a lot of dimples and a small area of cleavage plane in the tensile fracture. The number of dimples and cleavage steps of the fracture is gradually decreased at a higher pouring temperature. At the pouring temperature of 605 ℃, the tensile strength and elongation reach up to 229. 2 MPa and 3. 16%, respectively.

关 键 词：浇注温度 近液相线挤压铸造 AZ91D镁合金 微观组织 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG248.2[金属学及工艺—金属材料]