(1. 中南大學 材料科學與工程學院，長沙 410083；
2. 中南大學 有色金屬材料科學與工程教育部重點實驗室，長沙 410083)
摘 要: 在Gleeble-1500熱/力模擬機上，對Mg-10Gd-4.8Y-0.6Zr鎂合金進行高溫壓縮試驗，壓縮時設定應變速率范圍為0.001~1 s-1，溫度范圍為623~773 K，最大真應變?yōu)?.3；研究該合金高溫變形時流變應力與應變速率、變形溫度之間的關系及變形過程中的微觀組織演化；計算塑性變形表觀激活能及相應的應力指數(shù)；建立該合金的加工圖。結果表明：在該合金的加工圖中，功率耗散系數(shù)η隨應變速率的降低及溫度的升高而不斷增加，失穩(wěn)區(qū)域隨應變量的增加而擴大；綜合得出該合金的最佳實際變形工藝為溫度723~773 K、應變速率0.1~1 s-1。
關鍵字: Mg-10Gd-4.8Y-0.6Zr；高溫壓縮；加工圖；變形工藝參數(shù)
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, <）
Abstract:The processing parameters of Mg-10Gd-4.8Y-0.6Zr magnesium alloy were investigated. The tests were carried out in the strain rate range of 0.001-1 s-1 and temperature range of 623-773 K, and with the maximum true strain of 1.3 on hot-simulation machine Gleeble-1500. The relationships among the flow stress, the strain rate and the temperature as well as microstructure evolution were investigated. The apparent activation energy during plastic deformation and corresponding stress index were calculated, the processing maps were drawn. The test reveals that the efficiency of power dissipation increases with the increase of temperature and the decline of strain rate, and the instability region expands due to the rise of the temperature in processing maps. Optimal processing parameters were the temperature range of 723-773 K and the strain rate range of 0.1-1 s-1.
Key words: Mg-10Gd-4.8Y-0.6Zr; hot compression; processing maps; processing parameters
