(1. 東北大學(xué) 材料科學(xué)與工程學(xué)院，沈陽(yáng) 110006；
2. 西北有色金屬研究院 鈦合金研究院，西安 710016)
摘 要: 利用平面應(yīng)變壓縮實(shí)驗(yàn)，研究TC21G鈦合金在變形溫度為870~940 ℃、應(yīng)變速率為0.1~1 s-1條件下的變形行為，并分析顯微組織的演變過(guò)程。同時(shí)，研究加工參數(shù)對(duì)應(yīng)變硬化指數(shù)n值的影響。結(jié)果表明：在應(yīng)變速率一定的條件下，隨著變形溫度的升高，顯微組織中β相的含量增加，合金的流變應(yīng)力降低；而在變形溫度一定的條件下，隨著應(yīng)變速率的增加，可動(dòng)位錯(cuò)的遷移速率增加，從而使合金的流變應(yīng)力升高。TC21G鈦合金在兩相區(qū)進(jìn)行變形，隨著變形溫度的升高，應(yīng)變量的增加以及應(yīng)變速率的降低，片層α相的球化程度增加。基于顯微組織的分析可知，應(yīng)變硬化指數(shù)n值與絕熱升溫效應(yīng)，β相的動(dòng)態(tài)再結(jié)晶(DRX)以及動(dòng)態(tài)回復(fù)(DRV)有密切的關(guān)系。
關(guān)鍵字: TC21G鈦合金；平面應(yīng)變壓縮；動(dòng)態(tài)再結(jié)晶；應(yīng)變硬化指數(shù)
（1. School of Materials Science and Engineering, Northeastern University, Shenyang 110006, China;
2. Titanium Alloy Research Institute, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China）
Abstract:The hot deformation behavior in plane strain compression of the TC21G titanium alloy was investigated in the deformation temperatures ranging from 870 ℃ to 940 ℃, the strain rates ranging from 0.1 s-1 to 1 s-1. The microstructures evolution was also analyzed. Meanwhile, the effect of processing parameters on the strain hardening exponent n was analyzed. The results show that, under the condition of a certain strain rate, the flow stress of alloy decreases with the increase of the deformation temperature due to the increase of β phase content. However, in the condition of a certain temperature, the flow stress of alloy increases with the increase of the strain rate, because the velocity of mobile dislocations increases. During deforming in the α+β field, with the increase of the deformation temperature or strain, and the decrease of the strain rate, the globularization degree of the lamellar α phase increases. Based on the microstructure examination, the variation of n values is found to depend on the adiabatic heating effect, dynamic recrystallization (DRX) and dynamic recovery (DRV) of β phase.
Key words: TC21G titanium alloy; plane strain compression; dynamic recrystallization; strain hardening exponent
