不同凝固条件下Ni-Al合金相组成的变化

Phase Structure in Ni-Al Alloys Under Different Solidification Conditions

以Ｎｉ３Ａｌ合金为基，选取Ｎｉ７０Ａｌ３０，Ｎｉ７５Ａｌ２５，Ｎｉ８０Ａｌ２０３种成分的合金，利用Ｘ射线衍射仪（ＸＲＤ）定量分析了平衡凝固、常规凝固和快速凝固条件下相组成的变化．研究结果表明：快速凝固条件能够抑制β－ＮｉＡｌ相的形成；利用透射电镜（ＴＥＭ）观察到β－ＮｉＡｌ相的马氏体转变和预马氏体效应，并从晶体的形核及生长角度对上述现象进行了分析．

Abstract The phase structures of Ni 70 Al 30 ,Ni 75 Al 25 ,Ni 80 Al 20 alloys solidified under different solidification conditions were studied and quantitatively analysed using XRD. Martensite transformation of β-NiAl phase and pre-martensite effect were observed by means of TEM.The formation of β-NiAl phase could be restrained by rapid solidification. The mechanism leading to this effect was discussed with the current theory of crystal nucleation and growth.