(北京有色金屬研究總院 有色金屬加工事業(yè)部，北京 100088)
摘 要: 在Gleeble−1500D熱模擬機(jī)上采用等溫壓縮實(shí)驗(yàn)研究Zn-8Cu-0.3Ti鋅合金的高溫流變行為，獲得鋅合金在變形溫度為230~380 ℃、應(yīng)變速率為0.01~10 s−1和變形程度為50%條件下的真應(yīng)力-應(yīng)變曲線(xiàn)，根據(jù)動(dòng)態(tài)材料模型(DMM)建立鋅合金的熱加工圖。結(jié)果表明：Zn-8Cu-0.3Ti鋅合金在實(shí)驗(yàn)條件下具有正的應(yīng)變速率敏感性，流變應(yīng)力隨著應(yīng)變速率的增大而增大，隨著變形溫度的升高而減小，該合金的流變應(yīng)力行為可用Arrhenius方程來(lái)描述。在本研究條件下，Zn-8Cu-0.3Ti鋅合金在熱變形時(shí)存在一個(gè)失穩(wěn)區(qū)，即應(yīng)變速率0.2 s−1以上的區(qū)域；在應(yīng)變速率小于0.001 s−1和340~370 ℃溫度范圍內(nèi)，最大功率耗散系數(shù)為0.53，該安全區(qū)域內(nèi)合金的變形機(jī)制為動(dòng)態(tài)再結(jié)晶。
關(guān)鍵字: 鋅合金；流變應(yīng)力模型；高溫變形；加工圖
（Nonferrous Processing Division, General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:The hot compression deformation of Zn-8Cu-0.3Ti alloy was performed on Gleeble−1500D at temperature of 230−380 ℃, strain rate of 0.01−10 s−1, height direction reduction of 50%. The true stress-strain curves under different deformation conditions were obtained and the processing map was developed based on the dynamic material modeling (DMM). The results indicate that the flow stress is sensitive to the strain rate and the deforming temperature. The flow stress increases with increasing the strain rate, and decreases with increasing the deforming temperature, which can be described by a constitutive equation in the form of Arrhenius function. The processing map shows one unsteady zone of high temperature deformation of Zn-8Cu-0.3Ti alloy, which is above strain rate of 0.2 s−1. At the temperature of 340−370 ℃ and below the strain rate of 0.001 s−1, the peak efficiency of power dissipation is 0.53, in which zone the deformation mechanism is dynamics recrystallization (DR).
Key words: zinc alloy; flow stress model; high temperature deformation; processing map
