(南昌航空大學(xué) 航空制造工程學(xué)院，南昌 330063)
摘 要: 在變形溫度920~1040 ℃、應(yīng)變速率0.001~70.0 s-1條件下，采用Thermecmastor-Z熱模擬試驗(yàn)機(jī)研究Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85Nd合金在α+β兩相區(qū)變形時(shí)的流動(dòng)行為和塑性變形機(jī)制，得到優(yōu)化的工藝參數(shù)范圍。結(jié)果表明：該合金在α+β兩相區(qū)變形時(shí)的流動(dòng)應(yīng)力對(duì)變形溫度和應(yīng)變速率均較敏感，變形溫度較低時(shí)(920、950和980 ℃)，流動(dòng)應(yīng)力曲線呈流動(dòng)軟化特征，變形溫度較高時(shí)(1010和1040 ℃)呈穩(wěn)態(tài)流動(dòng)特征。失穩(wěn)變形工藝參數(shù)范圍為(920~930 ℃、0.2~70 s-1)和(1000~1040 ℃、1~70 s-1)范圍，該區(qū)域易產(chǎn)生局部流動(dòng)和機(jī)械失穩(wěn)。綜合加工圖及微觀組織觀察結(jié)果，優(yōu)化出的Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85Nd合金α+β兩相區(qū)變形時(shí)的工藝參數(shù)范圍為(1000~1030 ℃、0.001~0.1 s-1)及(920~935 ℃、0.001~0.003 s-1)，其塑性變形機(jī)制為超塑性成形。
關(guān)鍵字: Ti合金；變形行為；工藝參數(shù)優(yōu)化；加工圖
（School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nangchang 330063, China）
Abstract:The flow behavior and plastic deformation mechanism of Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85Nd alloy were studied by the hot compression, which was carried out on a Thermecmastor-Z simulator in the temperature range of 920-1040 ℃ and strain rate range of 0.001-70.0 s-1, and the optimization process parameter range was obtained. The results show that the flow stress of this alloy is sensitive to temperature and strain rate in the α+β range. The flow stress curves exhibit a flow softening behavior when the temperature is lower than or equal to 980 ℃; while the flow stress curves exhibit a steady-state characteristic when the temperature is higher than or equal to 1010 ℃. The processing map exhibits two instability fields: 920-930 ℃ at 0.2-70 s-1 and 1000-1040 ℃ at 1-70 s-1. In these instability fields, the flow location or mechanical instability occurs. Combining processing map with microstructure observation, the optimum deformation process parameters in α+β range for Ti-5.6Al-4.8Sn-2.0Zr- 1.0Mo-0.35Si-0.85Nd alloy are (1000-1030 ℃, 0.001-0.1 s-1) and (920-935 ℃, 0.001-0.003 s-1), respectively, and the corresponding plastic deformation mechanism is superplasticity deformation.
Key words: Ti alloy; defomration behavior; process parameter optimization; processing map
