(燕山大學(xué) 先進鍛壓成形技術(shù)與科學(xué)教育部重點實驗室，秦皇島 066004)
摘 要: 分別在室溫(RT)、393 K、513 K和633 K開展扭轉(zhuǎn)0.5~4 t的2A12鋁合金的高壓扭轉(zhuǎn)(HPT)變形實驗。通過對微觀組織和室溫力學(xué)性能進行觀察、測量和統(tǒng)計，闡明了微觀組織和力學(xué)性能隨HPT工藝參數(shù)的變化規(guī)律。結(jié)合斷口形貌和斷口區(qū)域組織特征，對HPT變形試樣的斷裂行為進行了研究。結(jié)果表明：在RT~513 K區(qū)間，扭轉(zhuǎn)0.5~4 t的HPT變形試樣的抗拉強度(TS)均得到較大程度提升，其中在393 K、513 K扭轉(zhuǎn)0.5 t的變形試樣的伸長率(EL)同時得到較大程度改善，取得較好的強化與韌化效果。在RT扭轉(zhuǎn)1 t的變形試樣在不損失塑性的同時展示出本研究的最高TS值，TS值增至初始材料的156%，表現(xiàn)出穿晶斷裂主導(dǎo)的混合斷裂機制。
關(guān)鍵字: 2A12鋁合金；高壓扭轉(zhuǎn)；力學(xué)性能；強化；韌化；斷裂機制
（Key Laboratory of Advanced Forging and Stamping Technology and Science, Ministry of Education, Yanshan University, Qinhuangdao 066004, China）
Abstract:The high pressure torsion (HPT) deformation experiments of 2A12 aluminum alloy with 0.5-4 turns were carried out at RT, 393 K, 513 K and 633 K, respectively. Through the observation, measurement and statistics of the microstructure and mechanical properties at RT, the variations of microstructure and mechanical properties with HPT parameters were clarified. The fracture behaviors of HPT deformed specimens were studied by combining fracture morphology and microstructure characteristics near the fracture. The results show that the tensile strengths of HPT-(0.5-4 t) specimens have been greatly improved within the temperature range of RT-513 K, among which the elongations of torsion deformed specimens with 0.5 t at 393 K and 513 K, respectively, have been greatly improved at the same time, showing a better strengthening and toughening effect. The torsion deformed specimen with 1 t at RT shows the maximum value of tensile strength in this study without loss of plasticity. Its tensile strength increases to 156% that of the initial material, showing a mixed fracture mechanism dominated by transgranular fracture.
Key words: 2A12 aluminum alloy; high pressure torsion; mechanical property; strengthening; toughening; fracture mechanism
