(哈爾濱工程大學(xué) 材料科學(xué)與化學(xué)工程學(xué)院，哈爾濱 150001)
摘 要: 利用保溫電磁攪拌制備半固態(tài)漿料，對Al-6.5%Mg合金的半固態(tài)流變鑄造進(jìn)行研究。實(shí)驗(yàn)中對該合金的常壓鑄造、液態(tài)壓鑄和半固態(tài)壓鑄所得鑄件的顯微組織、力學(xué)性能和拉伸斷口進(jìn)行分析比較。結(jié)果表明，常壓鑄造得到的Al-6.5%Mg合金組織為粗大的樹枝晶，力學(xué)性能較低；與常壓鑄造相比，液態(tài)壓鑄件的樹枝晶生長較為規(guī)則，枝晶得到細(xì)化，同時(shí)，液態(tài)壓鑄件的強(qiáng)度和塑性提高明顯；半固態(tài)壓鑄的顯微組織則為規(guī)則的球狀晶，與液態(tài)壓鑄相比，半固態(tài)壓鑄件的強(qiáng)度略有提高，表現(xiàn)出更好的塑性。
關(guān)鍵字: 流變鑄造；保溫電磁攪拌；球狀晶；強(qiáng)度；塑性
（College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China）
Abstract:Semi-solid rheocasting of Al-6.5% Mg alloy was studied by using the method of thermal electromagnetic stirring to prepare semi-solid slurry. The microstructure, mechanical properties and tensile fracture of the castings under the conditions of constant pressure casting, liquid metal die-casting and semi-solid die-casting were compared. The results demonstrate that the Al-6.5%Mg alloy produced by conventional casting has coarse dendritic grains with low mechanical properties. Compared with constant pressure casting, the dendritic grains from liquid metal die-casting are more regular and finer, the strength and plasticity of liquid metal die-casting are improved. The microstructure in semi-solid die-casting shows regular spherical grains. Compared with liquid metal die-casting, the strength in semi-solid die-casting is slightly improved, and showing a better plasticity.
Key words: rheocasting; thermal electromagnetic stirring; spherical grains; strength; plasticity
