镍基高温合金胞状枝晶界面定向凝固过程中的双晶竞争生长  

Bi-crystal Competitive Growth in a Nickel-Based Superalloy during Cell/Dendrite Directional Solidification

作　　者：杨初斌[1] 刘林[1] 赵新宝[1] 李亚峰[1] 张军[1] 傅恒志[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2013年第8期1622-1626,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金项目(50931004;51101120);国家重点基础研究发展计划项目(2010CB631202;2011CB610406);凝固技术国家重点实验室研究基金(09-BZ-2010;57-TZ-2011)

摘　　要：通过籽晶法控制晶体取向,研究了双晶镍基高温合金AM3胞状枝晶界面定向凝固过程中的双晶竞争生长。结果表明,两籽晶<001>取向的相对位置对晶粒竞争生长有很大的影响。双晶<001>取向在不同平面时,晶粒竞争生长的主要方式是通过物理阻挡,在晶界处处于阻挡优势的晶粒在竞争生长中胜出。对双晶的<001>取向在同一平面时,两籽晶以大角度背离发散生长时,在双晶的发散区容易生成杂晶。The bi-crystal competitive growth in a nickel-based superalloy AM3 during the cell/dendrite directional solidification was investigated using seed crystals. The results show that the relative position of 〈001〉 orientations in bi-crystal has a great influence on the competitive growth. For bi-crystal with 〈001〉 orientations grown in different planes, the competitive growth is dependent on physical blocking between the cell/dendrites. The grain playing dominant blocking at the grain boundary is survived during the competitive growth For bi-crystal with 〈001〉 orientations grown in the same plane, the two seed crystals with their preferred growth directions are far away from that of the maximum temperature gradient in a divergent way, and a stray grain may appear and grow as a single crystal

关 键 词：高温合金 定向凝固 竞争生长 胞状枝晶界面 

分 类 号：TG132.32[一般工业技术—材料科学与工程]