摘要
通过ＴＥＭ分析对Ｎｉ１０％Ｔｉ（％，质量分数，下同）合金时效早期相变过程的研究表明Ｎｉ１０％Ｔｉ合金过饱和固溶体先通过调幅分解机理分解为贫、富溶质区；随后富溶质区发生有序化，最后形成Ｌ１２型有序相Ｎｉ３Ｔｉ。同时发现，淬冷抑制了该合金固溶体的相分解过程。ＮｉＴｉ合金时效相变过程中存在调幅分解与有序化两种失稳模式共存现象。
In the paper,the mechanism of phase transformation of Ni 10%Ti alloy(mass fraction %) during early stage of ageing has been studied by means of transmission electron microscope(TEM).It is concluded that supersaturated solid solution of Ni Ti alloy first decomposes into solute rich and solute depleted zones by spinodal mechanism.Thereafter,the solute rich zone undergoes ordering to form ordered phase Ni 3Ti (L1 2 type).The solute depleted zone transforms into dilute Ni based solid solution due to spinodal decomposition and ordering taking place by turn.In the meantime,it is found that phase transformation in Ni Tialloy is suppressed during quenching.And,the process of phase transformation in the alloy deals with two kinds of instability mode,i.e.,spinodal and ordering.
基金
国家自然科学基金
关键词
时效
相变
镍钛合金
Ni Ti alloy, spinodal decomposition, ordering, aging, phase transformation.
