深过冷条件下Fe-Ni-P-B合金的纳米晶凝固组织与液相Spinodal分解  

NANOCRYSTALLINE STRUCTURES OF Fe-Ni-P-B ALLOY SOLIDIFIED AT LARGE UNDERCOOLING AND LIQUID SPINONAL DECOMPOSITION

作　　者：张长青[1] 姚可夫[1] 

机构地区：[1]清华大学机械工程系先进成形制造教育部重点实验室,北京100084

出　　处：《金属学报》2006年第8期870-874,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目05401310;清华大学基础研究基金项目091101107;国家纳米科技中心项目资助

摘　　要：采用玻璃融覆法(fluxing)提纯技术能显著提高Fe_(40)Ni_(40)P_(14)B_6合金的过冷度,并可获得深过冷条件下的凝固组织．研究结果表明,不同过冷度下Fe_(40)Ni_(40)P_(14)B_6的凝固组织存在显著差异,增加过冷度能大幅细化凝固组织．在深过冷条件下,能获得纳米晶凝固组织；当过冷度为360 K时,所制备的Fe_(40)Ni_(40)P_(14)B_6块体纳米晶合金的平均晶粒尺寸约为40 nm；当过冷度足够大时,获得的凝固组织具有液相Spinodal分解导致的网状组织特征．热力学分析结果表明,Spinodal分解所形成的网状组织的特征尺寸与熔体过冷度有关,过冷度越大,尺寸越小．The undercooling of Fe40Ni40P14B6 alloy melt can be enhanced greatly by using fluxing purification technique. The solidification structures of the alloy under different undercoolings are quite difference and with increasing undercooling the microstructure was refined significantly. When the undercooling is large enough, nanosize solidification structure can be obtained. In present work, at the undercooling of 360 K, the as-prepared bulk nanocrystalline alloy possesses the average grain size of 40 nm. It has been found that the alloy melt will experience Spinodal decomposition, resulting in the appearance of the network characteristics in solidified structure if the undercooling is large enough. The thermodynamics analysis results indicate that the characteristic sizes of the network structure resulted by Spinodal decomposition are close related to the undercooling of the alloy melt, the larger the undercooling, the smaller the grain size.

关 键 词：Fe-Ni—P-B合金 玻璃融覆法 SPINODAL分解 过冷度 纳米组织 

分 类 号：TG111.2[金属学及工艺—物理冶金]