(1. 湖南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410082；
2. 湖南大學(xué) 噴射沉積技術(shù)及應(yīng)用湖南省重點(diǎn)實(shí)驗(yàn)室，長沙 410082；
3. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 采用Gleeble-3500熱模擬試驗(yàn)機(jī)對Mg-5Zn-1Mn鎂合金進(jìn)行大變形(變形量為80%)熱壓縮實(shí)驗(yàn)，研究變形溫度為250~400 ℃、應(yīng)變速率為1~40 s-1范圍內(nèi)變形過程中合金的組織演變規(guī)律和流變行為。結(jié)果表明：該合金在上述工藝條件下進(jìn)行熱壓縮變形時(shí)均發(fā)生了明顯的動態(tài)再結(jié)晶，且高應(yīng)變速率下獲得的再結(jié)晶組織在較低應(yīng)變速率下更為均勻、細(xì)小。通過分析流變應(yīng)力變化過程中對應(yīng)的微觀機(jī)理，表明高應(yīng)變速率更利于Mg-5Zn-1Mn鎂合金實(shí)現(xiàn)大塑性變形。Mg-5Zn-1Mn合金的變形激活能隨著變形溫度的升高和應(yīng)變速率的增大而減小。
關(guān)鍵字: Mg-5Zn-1Mn合金；流變行為；高應(yīng)變速率；激活能
（1. College of Materials Science and Engineering, Hunan University, Changsha 410082, China;
2. Hunan Provincial Key Laboratory of Spray Deposition Technology and Application,
Hunan University, Changsha 410082, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The hot compression tests were performed on Mg-5Zn-1Mn alloy with the large deformation of 80% by the Gleeble-3500 material simulation machine. The microstructure evolution and flow behaviour were studied at the deformation temperature range from 250 to 400 ℃ and the strain rate range from 1 to 40 s-1. The dynamic recrystallization (DRX) occurs obviously during hot deformation, the DRX microstructure developed at high strain rate is more uniform, and the grain size is smaller than that developed at low strain rate. The severe plastic deformation of ZM51 magnesium alloy can be achieved more effectively at high strain rate compared to low strain rate by analyzing the microscopic mechanism during the change of flow stress. The hot deformation activation energy decreases with increasing the deformation temperature and strain rate.
Key words: Mg-5Zn-1Mn magnesium alloy; flow behaviour; high strain rate; activation energy
