高强度铸造铝铜合金微观组织对性能的影响
Influence of Microstructure on Mechanical Properties of High Strength Cast Aluminum-copper Alloy
李利华1, 毛 健1, 卢锦德2, 涂铭旌1
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作者单位:1.四川大学 材料科学与工程学院,四川 成都 610064; 2.贵州大学 材料科学与工程学院,贵州 贵阳 550003
中文关键字:Al-Cu铸造铝合金; 微观组织; 强度; 塑性
英文关键字:casting aluminum-copper alloy; microstructure; strength; plasticity
中文摘要:研究了微观组织对ZL205A系铸造铝铜合金热处理后强度和塑性的影响。结果表明:影响该合金强度和塑性性能的微观组织主要是晶粒尺寸、晶内、晶界沉淀相,弥散析出相和未固溶相。晶界处主要是θ相、N相、初生T相的混合组织,当呈针状或条状时恶化合金性能,当呈半连续的骨骼对合金性能影响较小。晶内细小弥散的二次T相是主要强化相,当T相聚集长大会降低强度。过剩相θ相,当呈大块分布时降低合金塑性,当呈细小均匀分布时对合金性能影响较小。
英文摘要:The influences of microstructure on strength and ductility of high strength cast Al-Cu alloy with heat treatment were studied. The results show that the main factors which have an influence on the strength and plasticity of Al-Cu alloy are crystalline size, precipitated phases in grain boundary, and dispersed and undissolved phases. The microstructure of the grain boundary phase is mixture structure which consists of matrix, θ(Al2Cu), a little N, and T(Al12Mn2Cu). The mixed phases with acicular shape can depress the mechanical performance of Al-Cu alloy, while the mixed phase with incontinuous skeleton profile can improve the mechanical properties of the alloy. The fine dispersed T phase in intracrystalline is one of the main strengthening phases for Al-Cu alloys, but which can decrease the strength of Al-Cu alloy when T phase aggregations or grain growth happens. The ductility of the alloy reduces when the undissolved θ phase presents block shape, however, the ductility is less influenced when the undissolved θ phase is finely distributed in matrix or grain boundary.