(深圳職業(yè)技術(shù)學(xué)院 工業(yè)中心， 深圳 518055)
摘 要: 采用CO2激光焊接系統(tǒng)對(duì)AZ61鎂合金材料進(jìn)行焊接， 研究?jī)煞N不同焊接工藝條件下激光焊接接頭的微觀組織和化學(xué)成分的情況， 并對(duì)焊接接頭進(jìn)行顯微硬度測(cè)試和接頭拉伸實(shí)驗(yàn)。結(jié)果表明： AZ61鎂合金CO2激光焊接接頭成形良好，焊縫區(qū)域晶粒明顯細(xì)化， 熱影響區(qū)減小， 焊縫區(qū)域主要由細(xì)小的α-Mg相及（α+Al12Mg17）等共晶體組成； 焊縫的化學(xué)成分中鋁含量明顯高于母材， 而鎂含量則低于母材；合金成分鋁的增加有利于焊縫區(qū)域晶粒細(xì)化和力學(xué)性能的提高。 焊接接頭區(qū)域的顯微硬度和抗拉強(qiáng)度都高于母材， 焊接接頭具有良好的力學(xué)性能， 說(shuō)明CO2激光焊接是焊接AZ61鎂合金材料的有效方法。
關(guān)鍵字: AZ61鎂合金； 激光焊接； 力學(xué)性能； 抗拉強(qiáng)度
laser welding method
（Industry Center, Shenzhen Polytechnic, Shenzhen 518055, China）
Abstract: The laser welding of AZ61 magnesium alloys was carried out using a CO2 laser welding experimental system. The microstructure and chemical composition of joints were investigated under two different process conditions. The microhardness measurement and tensile test were conducted for two typical joints. The results show that the joints with good appearance have been formed. A fine grained weld region is observed and no obvious heat effected zone is found. The weld zone mainly consists of small α-Mg phase, (α+Al12Mg17) and other eutectic phases. In the weld, the composition of aluminum increases while magnesium decreases compared with those of the base metal. The increase of aluminum benefits to refine the grain and improves the mechanical properties. The test results indicate that the microhardness and tensile strength of weld zone are higher than those of the base metal. Therefore, CO2 laser welding can provide an effective method to weld the AZ61 magnesium alloys.
Key words: AZ61 magnesium alloy; laser welding; mechanical properties; tensile strength
