耐磨铝硅铜合金的双面搅拌摩擦焊

Double-side friction stir welding of wear resistant aluminum silicon copper alloy

对10 mm厚的铝硅铜合金进行了双面搅拌摩擦焊接,研究了焊接接头的显微组织及力学性能.研究表明,铸态金属晶粒和硅粒子在双面搅拌摩擦焊接过程中得到细化,硅颗粒分布均匀化.反面焊道比正面焊道的晶粒细化和硅粒子均匀化作用更明显.异向焊接的接头强度较低,所有接头均断在焊缝的前进侧.同向焊接的接头强度较高,接头断裂位置取决于焊接参数.选用搅拌头旋转频率为950 r/min、焊接速度为10mm/min的参数焊接时,同向接头表面成形好、内部无缺陷,其强度可达母材的87.4%.

The 10 mm thick wear resistant Al-Si-Cu alloy plates were double-side friction stir welded（D-FSW）.The microstructure and mechanical properties of the joints were investigated.The results show that the as-cast Al grain and Si reinforcement particles in the weld are remarkably refined during friction stir welding.The distribution of Si particles in the weld is more uniform than that in as-received base metal.The refinement of the grains and the uniformity of Si particles in the second pass are better than those in the first one.The joints of double pass welding in opposite direction（OD joints） exhibit lower tensile strength than those of double pass welding in the same direction（SD joints）.All the OD joints fractured through the advancing side of the joints,while the fracture paths of SD joints depend on the welding parameters.The tensile strength of SD joints welding at a stirring tool rotating speed of 950 rpm and a welding speed of 10 mm·min-1 is up to 87.4% of the base metal.