OBSERVATION OF COMPETITIVE GROWTH IN A DIRECTIONALLY SOLIDIFIED NICKEL BASE SINGLE CRYSTAL SUPERALLOY
OBSERVATION OF COMPETITIVE GROWTH IN A DIRECTIONALLY SOLIDIFIED NICKEL BASE SINGLE CRYSTAL SUPERALLOY
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发表时间：
1997-10
影响因子：
2.3
通讯作者：
F. Hengzhi;He Guo;Xi＇an
中科院分区：
文献类型：
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作者：
F. Hengzhi;He Guo;Xi＇an
对一种镍基单晶高温合金进行了双晶和四晶竞争生长的实验，以模拟定向凝固过程中的竞争生长。晶粒取向由籽晶控制。结果表明，竞争生长取决于晶粒的相对取向及其与最大温度梯度方向的关系。在双晶和四晶竞争生长条件下，择优生长方向（镍基高温合金中的001）靠近最大温度梯度的晶粒比择优生长方向远离最大温度梯度的晶粒生长快。在双晶竞争生长中，如果两个籽晶的择优生长方向远离最大温度梯度方向，则第三晶粒可能以发散的方式出现并生长为单晶。
Experiments have been done on bi and tetra-crystal competitive growth in a nickel base single crystal superalloy to imitate the competitive growth during directional solidification. The grain orientations were controlled by seed crystals. Results show that the competitive growth is dependent on the relative orientations of grains and their relation with the direction of maximum temperature gradient. Grains with their preferred growth direction (001 in nickel base superalloy) nearer to maximum temperature gradient will grow faster than those with their preferred growth direction far away from maximum temperature gradient in the condition of bi-crystal as well as tetra-crystal competitive growth. A third grain may appear and grow as a single crystal if two seed crystals with their preferred growth directions are far away from that of maximum temperature gradient in a divergent way in bicrystal competitive growth.