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1、http://www.lwgjhc.comhttp://www.sdtsdfhq.cnhttp://www.xtlxlj.comhttp://www.lwjsgg.com铝合金材料施焊的均匀性分析铝是银白色的轻金属,具有良好的塑性、较高的导电性和导热性,同时还具有抗氧化和抗腐蚀的能力。铝极易氧化产生三氧化二铝薄膜,在焊缝中容易产生夹杂物,从而破坏金属的连续性,降低其机械性能和耐腐蚀性能。Aluminumisasilverywhitemetal,goodplasticity,highelectricalconductivityandthermalconductivity,butalsoh
2、astheabilityofoxidationresistanceandcorrosionresistance.Aluminumtoproduce3oxidation2aluminiumoxidethinfilm,pronetoinclusionsintheweld,whichdestroythecontinuityanduniformityofmetal,reduceitsmechanicalpropertiesandcorrosionresistance. 2铝合金材料的焊接难点2weldingdifficultyofaluminiumalloymaterials http:/
3、/www.lwgjhc.comhttp://www.sdtsdfhq.cnhttp://www.xtlxlj.comhttp://www.lwjsgg.com (1)极易氧化。在空气中,铝容易同氧化合,生成致密的三氧化二铝薄膜(厚度约0.1-0.2μm),熔点高(约2050℃),远远超过铝及铝合金的熔点(约600℃左右)。氧化铝的密度3.95-4.10g/cm3,约为铝的1.4倍,氧化铝薄膜的表面易吸附水分,焊接时,它阻碍基本金属的熔合,极易形成气孔、夹渣、未熔合等缺陷,引起焊缝性能下降。(1)easytooxidation.Easilywithoxygeninair,aluminu
4、m,generatedense3oxidation2aluminiumfilm(thicknessofabout0.1to0.2mum),highmeltingpoint(2050℃),wellabovethemeltingpointofaluminum,aluminumalloy(about600℃orso).Aluminadensityof3.954.10g/cm3,whichisabout1.4timesofaluminum,andaluminafilmonthesurfaceofeasyabsorptionmoisture,welding,it'sbasicwayofmetal
5、fusion,easilyformingdefectssuchaspores,slaginclusion,incompletefusion,causetheweldperformancedegradation.http://www.lwgjhc.comhttp://www.sdtsdfhq.cnhttp://www.xtlxlj.comhttp://www.lwjsgg.com (2)易产生气孔。铝和铝合金焊接时产生气孔的主要原因是氢,由于液态铝可溶解大量的氢,而固态铝几乎不溶解氢,因此当熔池温度快速冷却与凝固时,氢来不及逸出,容易在焊缝中聚集形成气孔。氢气孔目前难于完全避免,氢的来
6、源很多,有电弧焊气氛中的氢,铝板、焊丝表面吸附空气中的水分等。实践证明,即使氩气按gb/t4842标准要求,纯度达到99.99%以上,但当水分含量达到20ppm时,也会出现大量的致密气孔,当空气相对湿度超过80%时,焊缝就会明显出现气孔。(2)easytoproduceporosity.Aluminumandaluminumalloyweldingporosityisthemainreasonofthehydrogenareproducedwhen,becausealotofliquidaluminumcanbedissolvedhydrogen,hydrogenandalmostin
7、solublesolidaluminium,sowhenthetemperatureofthemoltenpoolisquicklycooledandsolidified,thehydrogendoesn'tescape,easyaggregationformationporosityintheweld.Hydrogenhydrogenholeisdifficulttocompletelyavoid,thesourceofmany,therea
