深过冷铜镍合金微观组织演化规律研究

利用深过冷快速凝固技术使Cu65Ni35合金获得了不同的过冷度，最大过冷度达到284 K。对快速凝固组织拍摄金相图片，系统研究了Cu65Ni35合金微观组织形貌特征及其演化规律。结果表明，Cu65Ni35合金在大过冷度范围和小过冷度范围内均出现了晶粒细化现象。对具有典型晶粒细化特征的Cu65Ni35合金组织进行电子背散射衍射（EBSD）检测，发现大过冷度组织和小过冷度组织具有完全不同的晶粒取向，小过冷度下的组织发生晶粒细化是由枝晶重熔碎断致使的，而大过冷度下的组织发生晶粒细化却是由应力诱导再结晶完成的。

Evolution Law of Microstructure of Deeply Undercooled Copper-Nickel Alloy

The use of deep undercooling rapid solidification technology resulted in different undercooling degrees of Cu65Ni35 alloy, with a maximum undercooling of 284 K. The microstructure morphology characteristics and evolution laws of Cu65Ni35 alloy were systematically studied by taking metallographic images of rapidly solidified microstructure. The results indicate that Cu65Ni35 alloy exhibits grain refinement phenomenon in both the large undercooling range and the small undercooling range. Electron backscatter diffraction detection was performed on the Cu65Ni35 alloy structure with typical grain refinement characteristics. It was found that the high undercooling structure and the low undercooling structure had completely different grain orientation information. The grain refinement of the structure under low undercooling was caused by dendrite remelting and fracture, while the grain refinement of the structure under high undercooling was achieved by stress induced recrystallization.