铸造铝合金的流动性、热裂倾向性和收缩率研究  

Study on the Fluidity,Hot Tearing Susceptibility and Shrinkage of Cast Aluminum Alloy

作　　者：邹国童 Zou Guotong(School of Materials Science and Engineering,Central South University,Changsha 410083,Hunan)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《福建冶金》2023年第2期31-34,共4页Fujian Metallurgy

摘　　要：本研究采用单螺旋模具、约束棒模具和锥形模具对A356铝合金(简称:A356)和低硅铸造铝合金(Al3.5Si0.5Mg0.4Cu,简称:低硅铝合金)的流动性、热裂倾向性和体收缩率进行了评估与分析。研究结果发现:在相同的浇注工艺下,低硅铝合金的流动长度小于A356,热裂倾向性大于A356,且收缩率较大;当提高浇注温度至770℃时,低硅铝合金的流动性增加了28.8%,热裂敏感系数增大至76,收缩性增大4.6%。造成两种铝合金铸造性能差异的主要原因是二者元素含量不同,低硅铝合金由于Si含量的降低,其凝固范围较宽,凝固模式趋向于“糊状凝固”,且在“脆性温度区间”停留时间较长,故展现出了比A356较差的流动性和更大的热裂倾向性,收缩率也较大。The fluidity,hot tearing susceptibility and shrinkage of A356 aluminum alloy(A356)and low-silicon cast aluminum alloy(Al3.5Si0.5Mg0.4Cu)were evaluated and analyzed by using single spiral mold,constraint-rod mold and cone mold,respectively.The results show that under the same casting parameter,the flow length of low-silicon aluminum alloy is smaller than A356,the hot tearing susceptibility is larger than A356,and the shrinkage percentage is larger.When the pouring temperature was increased to 770℃,the fluidity of low-silicon aluminum alloy increased by 28.8%,the HTS increased to 76,and the shrinkage percentage increased by 4.6%.Due to the decrease of Si content,the low-silicon aluminum alloy has a wider solidification range,tends to be"paste solidification"in the solidification mode,and has a longer residence time in the"brittle temperature range".Therefore,compared with A356,the low-silicon aluminum alloy shows poorer fluidity,greater thermal cracking tendency,and larger shrinkage rate.

关 键 词：铸造性能 凝固模式 低硅铝合金 流动性 热裂倾向性 

分 类 号：TG146.21[一般工业技术—材料科学与工程]