航空学报 > 2007, Vol. 28 Issue (增): 178-182

深过冷快速凝固Fe82.5Ni17.5合金的组织演化

陈豫增1,刘峰1,张连强2,冷庆军1,孙彬彬1,杨根仓1   

  1. 1西北工业大学 凝固技术国家重点实验室 2河南省鹤壁工贸学校
  • 收稿日期:2006-11-07 修回日期:2007-01-18 出版日期:2007-08-10 发布日期:2007-08-10
  • 通讯作者: 刘峰1

Solidification Structure Evolution in Undercooled Fe82.5Ni17.5Melts

CHEN Yu-zeng1,LIU Feng1,ZHANG Lian-qiang2,LENG Qing-jun1
SUN Bin-bin1,YANG Gen-cang1   

  1. 1State Key Lab of Solidification Processing, Northwest Polytechnical University 2Hebi Industrial and Economic School of Henan Province
  • Received:2006-11-07 Revised:2007-01-18 Online:2007-08-10 Published:2007-08-10
  • Contact:  LIU Feng1

摘要:

采用熔融玻璃净化结合循环过热的方法,使Fe82.5Ni17.5合金获得了330 K的最大初始过冷度。结合理论计算和组织观察,对Fe82.5Ni17.5合金在深过冷条件下的凝固行为和组织形成规律进行了研究。结果表明,过冷度ΔT<63 K时,合金的凝固组织为粗大的树枝晶;当63 K<ΔT<158 K时,凝固再辉所产生的重熔效应非常强烈,受此影响,初生的树枝晶被熔断,形成了细化的粒状晶组织;当过冷度进一步增大至158 K<ΔT<203 K时,再辉所产生的重熔效应大大降低,凝固组织进一步演变为发达的树枝晶组织;而当ΔT>203 K时,凝固组织的晶粒细化源于快速凝固体积骤变所产生收缩应力导致的初生枝晶碎断。

关键词: 快速凝固, 晶粒细化, 微观组织, Fe-Ni合金, 晶体生长

Abstract:

Fe82.5Ni17.5 alloys were undercooled by means of molten glass fluxing and cycling superheating methods. The maximum undercooling of 330 K was achieved. In combination of the theoretical calculations and experimental observations, the solidification behavior and structure formation mechanisms were systematically investigated. If the bulk undercooling ΔT<63 K, the coarsening dendritic structures result. When ΔT is in the range of 63 K<ΔT<158 K, influenced by the serious remelting, which is produced by recalescence, the primary dendrite is remelted into refined spherical crystals.

Key words: rapid , solidification,  ,  , grain , refinement,  ,  , microstructure,  ,  , Fe-Ni , alloy,  ,  , crystal , growth

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