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在MTS810试验机上进行了MX246A合金的热压缩试验,获得了不同变形条件下该合金的真应力-真应变曲线,建立了MX246A合金的热加工图。结果表明,Ni3Al基MX246A合金的流变应力随着变形程度的增加先达到峰值应力,之后逐渐降低,趋于稳态流变。在较高的应变速率变形时容易达到稳态流变,在较低的应变速率时,随着应变量从临界应变逐渐增大,流变应力单调递减,并且随着温度的升高,单调递减的速率逐渐增大。真应变量为0.7的MX246A合金的加工图上存在一个安全加工区,对应的温度在1 220℃附近,应变速率在0.001s-1附近。随着真应变量的增大,功率耗散峰值区域逐渐向高温区移动,功率耗散的微观机制随之由动态回复向γ′相的回溶转变。
The hot compression test of MX246A alloy was carried out on the MTS810 testing machine. The true stress-true strain curve of the alloy was obtained under different deformation conditions. The hot working diagram of MX246A alloy was established. The results show that the flow stress of Ni3Al-based MX246A alloy reaches the peak stress with the increase of the deformation degree, then decreases gradually and tends to steady-state flow. Steady-state rheology is easily reached at higher strain rates, and at lower strain rates, the flow stress decreases monotonically as the amount of strain increases from the critical strain, and decreases monotonically as the temperature increases The rate of increase gradually. True strain of 0.7 MX246A alloy processing map there is a safe processing zone, the corresponding temperature in the vicinity of 1 220 ℃, strain rate in the vicinity of 0.001s-1. With the increase of true strain, the peak area of power dissipation gradually moves to the high temperature area, and the microscopic mechanism of power dissipation changes from the dynamic recovery to the solution recovery of γ ’phase.