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碳化硅晶须增强铝复合材料具有高比强度、比刚度、耐高温等优点,其可焊性较差,但采用激光焊接方法,用合适的焊接规范,可得到外观及性能良好的焊接接头。激光焊的功率和保护气体对焊接接头强度影响很大,功率过小时,未焊透会使接头强度降低,功率过大将使SiC烧损严重且有氧化物、硅块等夹杂,使接头强度降低。对于厚度为2mm的对接缝,比较合适的功率为190W左右,此时脉冲频率30Hz、胀冲宽度7ms、焊接速度5mm/s,保护气体氮或氩的效果无差异,为降低成本,在SiGw/6061A1激光焊时建议用氮气保护。焊接接头强度可达142MPa,相当于母材强度的53％。为进一步提高焊接接头强度,加大保护气体流量,使用某些含脱氧剂的填料或加入Si粉等等应是合理途径。
Silicon carbide whisker reinforced aluminum composite has the advantages of high specific strength, specific stiffness and high temperature resistance, and its solderability is poor. However, the laser welding method and the proper welding specification can obtain the welded joint with good appearance and performance. The power and shielding gas of laser welding have a great influence on the strength of welded joints. When the power is too low, the strength of joints will decrease if the welding power is too low. If the power is too high, the SiC will be burned seriously, and inclusions such as oxides, . For the thickness of 2mm butt joint, the more appropriate power of about 190W, then pulse frequency of 30Hz, expansion stroke width of 7ms, welding speed 5mm / s, no protective effect of nitrogen or argon gas, in order to reduce costs, in SiGw / 6061A1 laser welding recommended nitrogen protection. Weld joint strength up to 142MPa, equivalent to 53% of the base metal strength. To further improve the strength of welded joints, increase the flow of shielding gas, the use of certain filler containing deoxidizer or adding Si powder should be a reasonable way.