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利用光学显微镜、扫描电子显微镜及X射线衍射分析手段研究Cu-2.7Be合金的铸态以及均匀化过程中的显微组织、相演变规律,确立Cu-2.7Be合金的均匀化制度。并从理论出发,研究该合金的扩散动力学过程,建立Cu-2.7Be合金的均匀化扩散方程。结果表明:铸态Cu-2.7Be合金内存在严重的枝晶偏析,其物相组成为α、β和γ,均匀化后室温水冷样品的相组成为α和β,而随炉冷样品的相组成为α和γ;当均匀化温度由750℃升至800℃时,合金枝晶偏析的消除加快;在800℃下均匀化20 h后样品的枝晶偏析基本消除,考虑到材料的后续可加工性确定最佳的均匀化工艺为800℃×20 h随炉冷。建立Cu-2.7Be合金均匀化时间t与枝晶间距(2L)、均匀化温度T之间的关系,即t=7 075.76L2exp(23 529.47/T),由此式得到的理论均匀化制度(800℃×23 h)与实验所得结果基本吻合。
The microstructure and phase evolution of Cu-2.7Be alloy during as-cast and homogenization were investigated by optical microscopy, scanning electron microscopy and X-ray diffraction analysis. The homogenization of Cu-2.7Be alloy was established. Based on the theory, the diffusion kinetics of the alloy was studied, and the uniform diffusion equation of Cu-2.7Be alloy was established. The results show that there are serious dendritic segregation in the as-cast Cu-2.7Be alloy, the phase composition is α, β and γ. After homogenization, the phase composition of the room-temperature water-cooled sample is α and β, When the homogenization temperature is increased from 750 ℃ to 800 ℃, the dendrite segregation of the alloy is accelerated. The dendritic segregation of the alloy is basically eliminated after the homogenization at 800 ℃ for 20 h. Considering the follow-up of the material Workability to determine the best homogenization process for the 800 ℃ × 20h with the furnace cold. The relationship between the homogenization time t of Cu-2.7Be alloy and the dendrite spacing (2L) and the homogenization temperature T (t = 7 075.76L2exp (23 529.47 / T)) was established. The theoretical homogenization system 800 ℃ × 23 h) and the experimental results are basically consistent.