摘要
针对Pb-Bi包晶合金中高速及低速定向凝固,利用最高界面生长温度判据以及充分形核和成分过冷准则,对Pb-Bi包晶合金定向凝固中初生α和包晶β两相的相互竞争规律进行预测。计算结果表明:在中高速凝固段,与Pb-26%Bi、Pb-28%Bi、Pb-30%Bi和Pb-34%Bi(质量分数)合金对应的α→β转变的临界生长速度分别为20、14、8.5和2 mm/s;在低速凝固段,合金的相选择图分为8个生长区,其中包括两相分别以单相生长区及两相混合生长区。利用该相选择图,结合温度梯度与凝固速度比值(G/V)及合金原始成分(C0)可预测相选择规律及组织形态。
Based on the directional solidification of Pb-Bi peritectie alloys with moderate or high and low growth velocities, the competition between the primary a and peritectic β phases was predicted by using the highest interface growth temperature criterion and the nucleation and constitutional undercooling criterion, respectively. The calculated results show that the critical growth velocities for α→β transition under moderate/high growth velocities are 20, 14, 8.5 and 2 mm/s for Pb-26%Bi, Pb-28%Bi, Pb-30%Bi and Pb-34%Bi (mass fraction) alloys, respectively. For the low growth velocities, the phase selection map is divided into 8 growth zones including the single phase growth zone and the growth zone of two phases mixed. The phase selection and microstructure morphology can be predicted by using the phase selection map combined with solidification rate ratio (G/V) and initial content of the alloy (Co).
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2012年第5期1304-1310,共7页
The Chinese Journal of Nonferrous Metals
基金
中国博士后科学基金资助项目(20110491492)
江西省青年科学基金资助项目(2011BAB216017)
江西省教育厅科技项目(GJJ12035)
关键词
Pb-Bi合金
包晶合金
定向凝固
相选择
Pb-Bi alloy
peritectic alloy
directional solidification
phase selection