Ti-1023合金铸锭的凝固组织研究

Study of the Crystallization Morphology of Ti-1023 Alloy Ingot

摘要:

采用有限体积法建立数值模型，将模拟得到的温度场、流场与实际铸锭的凝固组织建立对应关系，研究了工业化大规格Ti-1023合金铸锭的晶粒生长方向及晶粒形态转变。结果表明:通过温度梯度分量，预测的铸锭底部及边部柱状晶的晶粒生长方向（角度）与实际组织的重合度达到90%以上；绘制G-R（温度梯度-凝固速率）图形:等轴晶与柱状晶间有较为明显的分界线，且不同熔炼工艺下，柱状晶-等轴晶转变的临界参数值G*存在差异。

Abstract:

In this paper, a numerical model was established using the finite volume method to establish a corresponding relationship between the simulated temperature and flow fields and the actual solidification structure of the ingot. The grain growth direction and grain morphology transformation of the industrial-scale Ti-1023 alloy ingot were investigated. The results indicated that the predicted grain growth direction (angle) of columnar grain at the bottom and edges of the ingot coincides with the actual by more than 90% through temperature gradient components and ; The G-R (temperature gradient-solidification rate) diagram was plotted. There is an obvious boundary between equiaxed and columnar grains, and the critical parameters G* for columnar-equiaxed crystal transformation varies under different melting processes.