(1. 湖南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410082；
2. 蘇州有色金屬研究院有限公司，蘇州 215026)
摘 要: 在Gleeble−1500熱模擬機(jī)上對(duì)7150鋁合金進(jìn)行高溫?zé)釅嚎s實(shí)驗(yàn)，研究該合金在變形溫度為300~450 ℃和應(yīng)變速率為0.01~10 s−1 條件下的流變應(yīng)力行為。結(jié)果表明：流變應(yīng)力在變形初期隨著應(yīng)變的增加而增大，出現(xiàn)峰值后逐漸趨于平穩(wěn)；峰值應(yīng)力隨著溫度的升高而減小，隨著應(yīng)變速率的增大而增大；可用包含Zener-Hollomon參數(shù)的Arrhenius雙曲正弦關(guān)系來(lái)描述合金的熱流變行為，其變形激活能為226.698 8 kJ/mol；隨著溫度的升高和應(yīng)變速率的降低，合金中拉長(zhǎng)的晶粒發(fā)生粗化，亞晶尺寸增大，再結(jié)晶晶粒在晶界交叉處出現(xiàn)并且晶粒數(shù)量逐漸增加；合金熱壓縮變形的主要軟化機(jī)制由動(dòng)態(tài)回復(fù)逐步轉(zhuǎn)變?yōu)閯?dòng)態(tài)再結(jié)晶。
關(guān)鍵字: 7150鋁合金；熱壓縮變形；流變應(yīng)力；變形激活能；動(dòng)態(tài)再結(jié)晶
（1. College of Materials Science and Engineering, Hunan University, Changsha 410082, China;
2. Suzhou Nonferrous Metals Research Institute, Suzhou 215026, China）
Abstract:The flow stress behavior of 7150 aluminum alloy during hot compression deformation was studied by thermal simulation test at the deformation temperature of 300−450 ℃ and the strain rate of 0.01−10 s−1 on the Gleeble−1500 thermal-mechanical simulator. The results show that the flow stress increases with increasing strain and tends to be constant after a peak value. The peak stress increases with increasing strain rate, and decreases with increasing deformation temperature, which can be represented by a Zener-Hollomon parameter in the hyperbolic sine equation with the hot deformation activation energy of 226.6988 kJ/mol. With increasing temperature and decreasing strain rate, the elongated grains in the deformed samples are coarsened and the size of subgrain increases; the number of fine grain in grain boundary also increases, indicating that the main softening mechanism of the alloy during hot compression deformation transforms from dynamic recovery to dynamic recrystallization.
Key words: 7150 aluminum alloy; hot compression deformation; flow stress; hot deformation activation energy; recrystallization
