(內(nèi)蒙古工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，呼和浩特 010051)
摘 要: 針對(duì)分流模擠壓焊合部位的金屬在模具中難以取出進(jìn)行分析，設(shè)計(jì)了分析焊縫組織性能的簡(jiǎn)易模具；采用電子背散射衍射分析(EBSD)和拉伸試驗(yàn)，研究擠壓溫度對(duì)6005A鋁合金擠壓焊合組織性能的影響。結(jié)果表明：擠壓溫度為500~580 ℃ 時(shí)，6005A鋁合金焊合組織的平均晶粒尺寸呈先減小后增大的趨勢(shì)；當(dāng)在擠壓溫度為540 ℃時(shí)，焊合組織平均晶粒尺寸最小，約為52 μm，且此時(shí)的晶粒尺寸均勻程度最佳。焊合組織中小角度晶界所占比例較多，且隨著擠壓溫度的提高，小角度晶界的相對(duì)頻率都保持在65%左右。焊合部位的屈服強(qiáng)度和抗拉強(qiáng)度隨著擠壓溫度的升高呈先上升后下降的趨勢(shì)；當(dāng)擠壓溫度為540 ℃時(shí)，焊合組織的力學(xué)性能最好，屈服強(qiáng)度為 68.56 MPa，抗拉強(qiáng)度為119.87 MPa。
關(guān)鍵字: 6005A鋁合金；分流模擠壓；擠壓溫度；焊合區(qū)域；顯微組織；力學(xué)性能
（School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051, China）
Abstract:A new die was designed to solve the problem that the alloy was difficult to be taken out when it was welded by porthole die extrusion. The effect of the extrusion temperature on microstructure and mechanical properties of 6005A aluminum alloy was studied by electron backscattered diffraction (EBSD), combined with the mechanical tensile properties test. The results show that the average grain size of the welding zone will be reduced at first and then improved when the extrusion temperature is in the range of 500-580 ℃, the average grain size is the smallest of about 52 μm and the uniformity is the best at 540 ℃. The percentage of the low angle boundaries of welding zone is the highest and the relative frequency of low angle boundaries keeps at 65% with the rise of extrusion temperature. The tensile strength and yield strength of the welding zone will be improved at first and then reduced with the increase of extrusion temperature. And the mechanical property of 6005A aluminum alloy is the best at 540 ℃, the yield strength and tensile strength are 68.56 MPa and 119.87 MPa, respectively.
Key words: 6005A aluminum alloy; porthole die extrusion; extrusion temperature; welding zone; microstructure; mechanical property
