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Al-Cu-Ge合金是典型的三元共晶体系,在工业上有重要的应用价值,对其进行研究有助于了解该合金的热物理性质和提高该合金的结构性能.本文选择了Al55Cu10Ge35,Al70Cu10Ge20和Al80Cu10Ge10三种成分合金作为研究对象,对合金的固态比热和热膨胀系数进行了测量,并对比分析了合金在近平衡凝固和落管快速凝固条件下的组织特征和凝固路径.研究发现,合金比热随Al含量的增大和Ge含量的减少而增大.这三种成分合金的软化温度均为666 K,物理热膨胀系数α在370—650 K温度范围内基本一致,约为1.5×10-5K-1.近平衡凝固条件下合金凝固过程中最后一步反应生成的均为(Al)+(Ge)二相共晶而不是三元共晶,这表明(Al)、(Ge)和CuAl2相在这三种成分的Al-Cu-Ge合金中难以同时形核并协同生长.然而,在快速凝固条件下,初生相的形核和生成受到抑制,合金中更易于形成二相共晶和三元共晶组织.
Al-Cu-Ge alloy is a typical ternary eutectic system, which has an important industrial application value.It is helpful to know its thermophysical properties and improve the structural properties of the alloy.In this paper, Al55Cu10Ge35 , Al70Cu10Ge20 and Al80Cu10Ge10 as the research object, the solid specific heat and thermal expansion coefficient of the alloy were measured, and the microstructure and solidification path of the alloy were analyzed and compared under the conditions of near-equilibrium solidification and rapid solidification of drop tube. , The specific heat of the alloy increases with the increase of Al content and the decrease of Ge content.The softening temperature of these three components alloy are both 666 K and the physical thermal expansion coefficient α is basically the same in the temperature range of 370-650 K, 10-5K-1. The (Al) + (Ge) two-phase eutectic instead of the ternary eutectic was formed during the final reaction during the solidification of the alloy under nearly equilibrium conditions, indicating that (Al), The CuAl2 phase is difficult to nucleate simultaneously and co-grow in the Al-Cu-Ge alloys of these three components.However, the nucleation and formation of the primary phase are inhibited under rapid solidification conditions, and the formation of two-phase eutectic And ternary eutectic.