喷射沉积耐热铝合金AlFeVSi本构方程的研究

Study on Constitutive Equation of Heat-resistant Aluminium Alloy AlFeVSi Prepared by a Spray Deposition-extrusion Route

对采用喷射沉积制备的Al-Fe-V-Si耐热铝合金，在Gleeble-1500热模拟机上于350-480℃、应变速率0．05s^-1、0．014s^-1、0．0014s^-1条件下进行高温压缩热模拟实验研究。结果表明，流变应力随变形温度的升高而降低，随应变速率的提高而增加，且均随变形程度的增加呈现出达到峰值后逐渐下降的趋势。在实验的基础上分析了变形激活能与变形温度、应变速率以及应力指数和流变应力之间的关系，最后回归出了包含激活能Q和温度T的双曲正弦形式的本构方程，为合理制定Al-Fe-V-Si耐热铝合金的热挤压工艺提供了理论和实验依据。

The flow stress features of A1FeVSi heat-resistant aluminum alloy prepared by a spray depositionextrusion route are studied by the isothermal compression test using Gleeble-1500 hot simulator. The compression teat is performed in the temperature range of 350℃ to 480℃ and at the strain rate range of 0. 05s^-1,0. 014s^-11,0. 0014s^-1. The results show the flow stress is controlled by both strain rate and deforming temperature, and the flow stress decreases with the increase of deforming temperature, while increasing with the increase of strain rate. The flow stress decreases after a peak value with the increasing strain, showing dynamic recrystallization. The deformation activation energy and stress exponent are analyzed. At last the flow-stress equation , that is Sellars-Tegart equation, is acquired by the means of nonlinear fit.