(1. 中南大学 粉末冶金国家重点实验室,长沙 410083;
2. 湘潭大学 材料设计及制备技术湖南省重点实验室,湘潭 411105)
摘 要: 研究固态Zn/Fe 及Zn/Fe-Si扩散偶中金属间化合物的生长及硅的影响。对扩散偶在385 ℃下扩散30~ 300 min的研究结果表明:在Zn/Fe扩散偶中,扩散层以δ相为主,ζ相和δ相之间具有平直的界面,随扩散时间的延长,δ相的厚度增加,ζ相逐渐被消耗,至退火300 min时,dζ/dδ的值为0;但在Zn/Fe-Si扩散偶中,扩散层以ζ相为主,δ相呈小岛状伸入到ζ相层中,铁基体中的硅促进扩散初期ζ相的生长而抑制δ相的生长,并使δ层在扩散后期为完全的线性生长。3个扩散偶中总扩散层的生长均由扩散控制。
关键字: Zn-Fe金属间化合物;扩散偶;显微组织;生长动力学
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
2. Key Laboratory of Materials Design and Preparation Technology of Hunan Province, Xiangtan University, Xiangtan 411105, China)
Abstract:The growth of Zn-Fe intermetallic compounds and the effect of Si were studied by means of diffusion experiments at 385 ℃ for 30−300 min. The results show that the diffusion layers is mainly composed of δ phase in Zn/Fe couples, the interface between ζ and δ phases is planar, the thickness of δ phase increases and ζ phase decreases with time, dζ/dδ is zero at 300 min. In Zn/Fe-Si couple, the diffusion layers is mainly composed of ζ phase, δ phase protrudes into ζ phase in island shape, and the silicon in iron promotes the growth of ζ phase and restrains the growth of δ phase in the initial period, δ phase increases linearly with the increase of time in the later period. The growth of the total layer in three couples is diffusion-controlled.
Key words: Zn-Fe intermetallic compounds; diffusion couple; microstructure; growth kinetics