(西安建筑科技大學(xué) 冶金工程學(xué)院，西安 710055)
摘 要: 采用水下攪拌摩擦焊接技術(shù)(Submerged friction stir welding, SFSW)對2024-T4鋁合金板材進(jìn)行連接，研究攪拌頭轉(zhuǎn)速對SFSW接頭焊接溫度場、焊核區(qū)析出相形貌以及接頭力學(xué)性能的影響。結(jié)果表明：循環(huán)水冷介質(zhì)具有明顯的瞬時(shí)快冷作用；隨著攪拌頭轉(zhuǎn)速從600 r/min增大到1 180 r/min，SFSW接頭焊接溫度場峰值由271.0 ℃增大到310.8 ℃；焊核區(qū)析出相在熱循環(huán)作用下析出并長大。析出相的數(shù)量逐漸增多，尺寸增大；SFSW接頭焊核區(qū)顯微硬度平均值由117.5HV降低至99.2HV、抗拉強(qiáng)度和伸長率分別由403.3 MPa和3.24%降低至334.5 MPa和1.44%。
關(guān)鍵字: 鋁合金；水下攪拌摩擦焊接；轉(zhuǎn)速；組織；性能
（College of Metallurgical Engineering, Xi’ an University of Architecture and Technology, Xi’ an 710055, China）
Abstract:2024-T4 aluminum alloy plate was jointed by submerged friction stir welding (SFSW). The effects of rotation speed on the welding temperature fields of SFS weld, precipitate morphology of the nugget zone and mechanical properties of SFS weld were investigated. The results show that the cooling water circulation medium has significant instantaneous cooling effect; the peak value of welding temperature fields increases from 271.0 ℃ to 310.8 ℃ with the rotation speed increases from 600 r/min to 1180 r/min. The precipitate phases of the nugget zone precipitate and grow under welding thermal cycle. The quantity and size of the precipitates gradually increase with the increase of the rotation speed. The average value of microhardness in the nugget zone of SFS weld decreases from 117.5HV to 99.2HV with the increase of the rotation speed, meanwhile, tensile strength and elongation of SFS weld decrease from 403.3 MPa and 3.24% to 334.5 MPa and 1.44%, respectively.
Key words: aluminum alloy; submerged friction stir welding; rotation speed; microstructure; properties
