(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院, 長(zhǎng)沙 410083；
2. 中南大學(xué) 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室, 長(zhǎng)沙 410012；
3. 中國(guó)航天科學(xué)和工業(yè)集團(tuán) 防御技術(shù)研究試驗(yàn)中心，北京 100854)
摘 要: 采用Geeble-1500熱模擬實(shí)驗(yàn)機(jī)對(duì)Mg-6Gd-3Y-0.5Zr合金進(jìn)行熱壓縮實(shí)驗(yàn)，設(shè)定變形溫度為623~773 K、變形速率為0.001~1 s-1、最大真應(yīng)變?yōu)?.6，利用指數(shù)函數(shù)關(guān)系計(jì)算合金的表觀激活能，并建立合金的表觀激活能圖。根據(jù)動(dòng)態(tài)材料模型(DMM)計(jì)算該合金的加工圖，綜合分析合金的表觀激活能圖、加工圖以及m、 、S和 這4個(gè)判據(jù)得到：在723 K、0.01 s-1以及773 K、0.1 s-1的條件下，該合金能夠獲得穩(wěn)定的塑性變形，并確定為該合金的最佳變形工藝。結(jié)合表觀激活能圖、加工圖以及m、 、S和 這4個(gè)判據(jù)，能夠更加準(zhǔn)確地判斷合金塑性失穩(wěn)的工藝范圍。
關(guān)鍵字: Mg-Gd-Y-Zr合金；熱壓縮；加工圖；表觀激活能；塑性失穩(wěn)判據(jù)
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials, Ministry of Education, Central South University, Changsha 410012, China;
3. Defense Technology Research and Test Center, China Aerospace Science and Industry Corporation, Beijing 100854, China）
Abstract:The hot compression tests were performed on Mg-6Gd-3Y-0.5Zr alloy at the deformation temperatures of 623-773 K, strain rates of 0.001-1 s-1 and the maximum true strain of 0.6 by using Geeble-1500 test machine. The apparent activate energy was calculated according to exponential function, and the apparent activate energy map was established. The processing map was obtained according to dynamic materials model (DMM). The optimum deformation conditions when the alloy can obtain the stable plastic deformation are obtained at condition of 723 K, 0.01 s-1 and 773 K, 0.1 s-1 by analyzing the apparent activate energy map, processing map and four criteria of m, , S and systematically. A more accurate range of the conditions for instable deformation can be determined by analyzing the apparent activate energy map, processing map and four criteria.
Key words: Mg-Gd-Y-Zr alloy; hot compression; processing map; apparent activate energy; plastic instability criteria
