基于响应面法的Ti2AlNb基合金工艺参数优化研究

Optimization of Process Parameters of Ti2AlNb-based Alloys Based on Response Surface Methodology

摘要:

本文采用Gleeble-3500热模拟试验机对Ti2AlNb基合金进行了变形温度为650-850℃、应变速率0.001-1s-1的压缩实验，研究其热变形行为，获得Ti2AlNb基合金最优工艺参数范围。首先分析Ti2AlNb基合金的流变应力曲线，并计算热变形激活能Q、lnZ和功率耗散因子η，从而建立以热变形激活能Q、lnZ和功率耗散因子η的二阶响应面模型，再通过多目标可视化优化得出Ti2AlNb基合金优化后的最佳区域，并结合微观组织图验证。结果表明Ti2AlNb基合金随变形温度升高和应变速率减小流变应力随之减少；建立的响应面模型具有较高精度，可以用于工艺参数的优化与分析；多目标可视化优化结果得出Ti2AlNb基合金优化后的最佳区域是变形温度750-850℃、应变速率0.01-0.03s-1。

Abstract:

In this paper, the hot deformation behavior of Ti2AlNb-based alloy was studied by using Gleeble-3500 thermal simulation experiment machine to carry out compression experiments with deformation temperature of 650-850℃ and strain rate of 0.001-1s-1, and the optimal process parameter range of Ti2AlNb-based alloy was obtained. First, the flow stress curve of Ti2AlNb-based alloy is analyzed, and the hot deformation activation energy Q, lnZ and power dissipation factor are calculated η, so as to establish the thermal deformation activation energy Q, lnZ and power dissipation factor η, the second order response surface model of Ti2AlNb-based alloy was established, and the optimal region after optimization was obtained through multi-objective visual optimization, which was verified with the microstructure diagram. The results show that the flow stress of Ti2AlNb-based alloys decreases with increasing deformation temperature and decreasing strain rate. The established response surface model has high accuracy, which can be used for optimization and analysis of process parameters; the results of multi-objective visual optimization show that the optimal region of Ti2AlNb-based alloy after optimization is the deformation temperature of 750-850℃ and the strain rate of 0.01-0.03s-1.