及工藝優(yōu)化
(北京有色金屬研究總院，北京 100088)
摘 要: 在Gleeble−1500D熱模擬機(jī)上研究了ZnAl10Cu2合金在變形溫度為180～330 ℃、應(yīng)變速率為0.01～10 s−1、最大變形量為0.7條件下的熱變形行為，采用動態(tài)材料模型的Murty失穩(wěn)準(zhǔn)則繪制了ZnAl10Cu2合金的熱加工圖，結(jié)合微觀組織觀察研究了該合金在實(shí)驗(yàn)條件下的微觀變形機(jī)制及流動失穩(wěn)現(xiàn)象，并優(yōu)化了熱變形的工藝參數(shù)。結(jié)果表明：ZnAl10Cu2合金在高應(yīng)變速率區(qū)域容易發(fā)生流變失穩(wěn)現(xiàn)象，45°剪切開裂、絕熱剪切帶和局部塑性流動是流動失穩(wěn)區(qū)的主要變形機(jī)理，在變形安全區(qū)片狀α1和α2相均發(fā)生了不同程度的球化和扭折，且基體β相發(fā)生了動態(tài)再結(jié)晶，在變形溫度為240 ℃、應(yīng)變速率為0.1 s−1時，能量耗散率達(dá)到峰值，約為53%。
關(guān)鍵字: ZnAl10Cu2合金；熱加工圖；顯微組織；絕熱剪切帶；球化
ZnAl10Cu2 alloy based on Murty criterion
（Beijing General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:The hot deformation behavior of ZnAl10Cu2 alloy was studied by compression testing on a Gleeble−1500D simulator in the temperature range from 180 ℃ to 330 ℃ and true strain rate range from 0.01 s−1 to 10 s−1 at the maximum true strain of 0.7. A processing map was developed on the basis of Murty instability criterion of dynamic material model. The micro-deformation mechanism and the flow instability phenomena of ZnAl10Cu2 alloy were studied by the microstructure under the experimental conditions, and the optimum processing parameters were evaluated. The results show that ZnAl10Cu2 alloy exhibits flow instability at high strain rate. The 45° shear cracking, adiabatic shear band and the local plastic flow are the main deformation mechanisms. The globalization and kinking of the laminar α1 and α2 phases are observed in the stable domain, and the dynamic recrystallization of β phase is also observed in the stable domain. At deformation temperature of 240 ℃ and strain rate of 0.1 s−1, the power dissipation rate reaches the peak, which is about 53%.
Key words: ZnAl10Cu2 alloy; processing map; microstructure; adiabatic shear band; globalization
