(1. 武漢工程大學 機電工程學院，武漢 430073；
2. 華中科技大學 材料成形與模具技術國家重點實驗室，武漢 430074)
摘 要: 利用光學顯微鏡(OM)、掃錯電鏡(SEM)等對真空低壓消失模殼型鑄造和消失模鑄造A356鋁合金的組織和性能進行對比分析。結果表明：真空低壓消失模殼型鑄造A356鋁合金組織比消失模鑄造A356鋁合金組織細小、致密，其初生相晶粒尺寸和共晶硅尺寸都遠小于消失模鑄造鋁合金的，孔隙率低于消失模鑄造鋁合金的、密度高于消失模鑄造鋁合金的。真空低壓消失模殼型鑄造A356合金的拉伸斷裂方式以韌性斷口為主，消失模鑄造鋁合金的斷裂方式以脆性斷口為主；鑄件經T6熱處理后的抗拉強度、伸長率和布氏硬度分別達到278.27 MPa、8.10 %和93.1HB，較消失模鑄件的分別提高了20.2 %、166.4 %和17.6 %；其鑄件表面質量也優(yōu)于消失模鑄件的表面質量。
關鍵字: 鋁合金；真空低壓消失模殼型鑄造；消失模鑄造；組織；性能
（1. School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, Wuhan 430073, China;
2. State Key Laboratory of Material Processing and Die ＆ Mould Technology,
Huazhong）
Abstract:The microstructures and properties of A356 alloy produced using expendable pattern shell casting process with vacuum and low-pressure (EPSC-VL) were compared with those of lost foam casting (LFC) process by OM and SEM techniques. The results show that microstructure of A356 alloy produced by EPSC-VL is finer and denser than that of LFC, and the sizes of the primary phase and eutectic silicon are far less than those of LFC, its porosity is less than that of LFC, and its density is higher than that of LFC. The fracture mechanism of A356 alloy obtained using EPSC-VL mainly shows ductile fracture, and that of A356 alloy obtained using LFC mainly shows brittle fracture. The tensile strength, elongation as well as hardness of A356 after T6 treatment alloy fabricated using EPSC-VL are respectively 278.27 MPa, 8.10% and 93.1HB, and are respectively 20.2%, 166.4% and 17.6% higher than those of LFC. Furthermore, the surface roughness of castings made by EPSC-VL is better than that of LFC.
Key words: aluminum alloy; expendable pattern shell casting with vacuum and low-pressure; lost foam casting; microstructure; properties
