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在高真空下，采用熔融玻璃净化与循环过热相结合的方法．在 ２２—２７０ Ｋ过冷度范围内，研究Ｔ Ｃｕ_７０Ｎｉ_３０合金凝固组织形态演化过程．在△Ｔ＜△Ｔ~＊_２（１２０Ｋ）过冷度范围内，随着过冷度增大，枝晶渐变为粒状晶，发生了组织的第一类粒化．组织观察及成分分析结果表明，枝晶段之间偏析区不是晶界．第一类粒状晶的形成过程包括：枝晶在再辉期间发生熔断．从而形成枝晶段；然后枝晶段通过合并－再结晶而形成粒状晶．
In the high vacuum, the use of molten glass purification cycle combined with the method of overheating. In the range of 22-270 K subcooling, the solidification microstructure evolution of T Cu 70 Ni 30 alloy was studied. Within the range of undercooling of △ T <△ T ~ * _2 (120K), the dendrite gradient became granular crystal with the increase of supercooling degree, and the first type of granulation occurred. Tissue observation and composition analysis showed that the segregation zone between dendrite segments is not a grain boundary. The formation of the first type of granular crystals includes: dendrites fuse during reflow. Thereby forming a dendritic segment; then the dendritic segment forms a granular crystal by merging-recrystallization.