冷却速率对石膏型铸造铝合金组织及性能的影响  

Effects of Cooling Rate on Microstructure and Mechanical Properties of Plaster Casting Aluminum Alloy

作　　者：徐超 张国伟[1] 牛经纬 Xu Chao;Zhang Guowei;Niu Jingwei(School of Materials Science and Engineering,North University of China)

机构地区：[1]中北大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2020年第12期1376-1379,共4页Special Casting & Nonferrous Alloys

摘　　要：研究了不同冷却速率对石膏型铸造ZL205A铝合金不同壁厚位置处的显微组织及力学性能变化。结果表明,随着冷却速率提高,合金的晶粒明显细化;当冷却速率较小时,不同壁厚处合金的晶粒尺寸和力学性能存在梯度差,提高冷却速率,可以使铸件各部位显微组织和力学性能变均匀;当放置30mm厚冷铁时,铸件各部位平均晶粒尺寸最小,约为70μm,抗拉强度达389.8MPa,但伸长率仅为5.4%。The effects of different cooling rates on the microstructure and mechanical properties at different wall thickness locations of the plaster casting ZL205Aalloy were investigated.The results indicate that the grain size of alloy is obviously refined with the increase of the cooling rate.When the cooling rate is low,the grain size and mechanical properties of the alloy exist gradients at different wall thicknesses,and microstructure and mechanical properties of each part of the alloy can be fairly well-distributed by increasing the cooling rate.When a 30mm thick cold iron is placed,the average grain size of each part of alloy reach 70μm,and the average tensile strength reaches 389.8MPa,while the elongation is only 5.4%.

关 键 词：冷却速率 石膏型铸造 ZL205A合金 

分 类 号：TG249.5[机械工程—精密仪器及机械] TG146.21[金属学及工艺—铸造]