一种基于高温合金超薄件的晶粒细化剂及其与铸造工艺适应性研究  

A Grain Refiner Based on Superalloys Ultrathin Parts and Its Casting Process Adaptability

作　　者：蔡文波[1] 杨金侠[2] 孟杰[2] CAI Wen-bo;YANG Jin-xia;MEMG Jie(Naval Equipment Department,Xi'an 710021,Shaanxi,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China)

机构地区：[1]海军装备部,陕西西安710021 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《铸造》2022年第9期1083-1088,共6页Foundry

基　　金：国家科技专项(Y2019-Ⅶ-0011-0151)。

摘　　要：基于高温合金薄壁件超高温浇注导致粗大晶粒和柱状晶形成的问题,进行细化剂成分优化设计,并调整细化剂的添加量和粒度,制备不同晶粒尺寸的高温合金试样。通过对晶粒和微观组织进行观察,分析了晶粒细化机理及其工艺适应性。结果表明,细化剂芯部的C、Al、Cr、Nb、Co和Ti等元素具有异质形核作用,外部的Ni、W、Nb元素具有抑制细化剂高温衰退的作用;细化剂中Ti、Nb、W和Cr通过形成碳化物增加形核质点;Ti通过与Al生成正方晶格的TiAl进行异质形核;Co直接作为面心立方晶格(相的形核基底),或者借助与Al生成体心正方晶格结构的CoAl来增加形核基底,起到细化晶粒作用。在薄壁件浇注温度要求的1545~1 635℃范围内保证晶粒细化效果的前提下,提出了细化剂的添加量、粒度和保温时间等参数的适宜范围。Based on the formation of coarse grains and columnar crystals caused by ultra-high temperature pouring of thin-walled parts, the composition of refiner was optimized, and the addition amount and particle size of the refiner were adjusted to prepare superalloy samples with different grain sizes. The grains and microstructure were observed by optic microscope(OM), scanning electron microscope(SEM) and transmission electron microscope(TEM), and the refining mechanism and process adaptability were analyzed. The results showed that the elements C, Al, Cr, Nb, Co and Ti in the core of the refiner had heterogeneous nucleation, and the external elements Ni, W and Nb could inhibit the high temperature decay of the refiner;Ti, Nb, W and Cr in the refiner increased nucleation substrate by forming carbides;Ti was heteronucleated by TiAlwith a square lattice;Co directly act as the nucleation substrate of face centered cubic lattice( phase, or increased the nucleation substrate by generating CoAl with a body centered square lattice structure, which refined grains).On the premise of ensuring the refining effect within the required pouring temperature range of 1 545-1 635 ℃,the appropriate range of process parameters such as the amount of refiner, particle size and holding time was provided.

关 键 词：高温合金 细化机理 细化剂 工艺适应性 异质形核 

分 类 号：TG146.2[一般工业技术—材料科学与工程]