摘要
以一种第三代镍基单晶高温合金模型叶片为研究对象,采用ProCAST&CAFE数值模拟方法并结合HRS定向凝固实验,考察了不同抽拉速率与突变截面尺寸时,铸件截面突变处的温度场分布以及晶粒组织演化过程,分析了抽拉速率与突变截面尺寸对杂晶形成的影响规律。结果表明,增大抽拉速率与突变截面尺寸会显著改变凝固界面处的温度场分布,造成了突变截面边缘局部过冷区的形成,使得杂晶在该处形核长大。随着抽拉速率和突变截面尺寸的增大,杂晶数量增多且尺寸增大。
For the model blade of a kind of 3rd-generation Ni-base single crystal superalloy, the temperature field distribution and grain microstructure evolutionary process with different withdrawal rate and platform dimension was observed. By ProCAST ＆ CAFE numerical simulation and HRS directional solidification, the effect of withdrawal rate and platform dimension on stray grain formation was studied. The results show that the temperature field distribution near the solidification interface will be notably changed with the increased withdrawal rate and platform dimension. The stray grain will nucleate and grow at the platform edge due to the local undercooling. With the increased withdrawal rate and platform dimension, both the quantity and the size of the stray grain will increase.
出处
《铸造》
CAS
CSCD
北大核心
2014年第2期128-131,137,共5页
Foundry
基金
国家高技术研究发展计划项目(2012AA03A511)
国家重点基础研究发展计划项目(2010CB631202)
国家自然科学基金项目(50931004
51101120
51171151和51331005)资助
关键词
镍基单晶高温合金
杂晶
突变截面
抽拉速率
Ni-base single-crystal superalloy
stray grain
platform
withdrawal rate
