(中北大学 材料科学与工程学院,太原 030051)
摘 要: 基于三元微观相场动力学模型,研究弹性畸变能对于Ni75Al15Ti10合金早期沉淀过程的影响。结果表明:合金沉淀过程经历了从L10相向L12相的转变,且通过定量分析确定最终沉淀产物为复杂的Ni3(AlTi)相;加入弹性畸变能可以缩短合金从无序到有序转变的时间,同时促使其沿着特定的弹性“软”方向生长,最终形成高度择优取向的共格显微组织。此外,沉淀相内部主要存在NiAl以及AlNi这两种反位缺陷结构,畸变能的引入可以降低反位缺陷浓度,同时提高正位原子占位几率。
关键字: 微观相场;弹性畸变能;Ni75Al15Ti10;反位缺陷
(College of Materials Science and Engineering, North University of China, Taiyuan 030051, China)
Abstract:Based on the ternary microscopic phase-field dynamic model, the effect of elastic strain energy on Ni75Al15Ti10 alloy precipitation process was studied. The results indicate that the precipitation process experiences from the L10 to L12 phase transformation process and the final precipitated phase is Ni3(AlTi) by quantitative analysis. Meanwhile, the elastic strain energy can accelerate the process of transformation from disorder to order, promotes the growth alone the specific elastic “soft” direction, and finally forms coherent microstructure of highly ordered orientation. Furthermore, the main existence of NiAl and AlNi in the precipitation phase is the structure of the two kinds of anti-site defects, and the elastic strain energy can inhibit the generation of anti-site defects, and promote the positive position of atoms to occupy the corresponding lattice point.
Key words: microscopic phase field; elastic strain energy; Ni75Al15Ti10; anti-site defect