AZ80M镁合金搅拌摩擦连接区性能分析

Performance Analysis of Friction Stir Joint Zone for AZ80 M Magnesium Alloy

选用4mm厚AZ80M镁合金进行搅拌摩擦连接试验,搅拌头旋转速度固定为1000rpm,搅拌头前进速度分别为150mm/min、200mm/min和250mm/min,分析各参数下获得试样的微观组织、抗拉强度、显微硬度及耐腐蚀性能。结果显示,各参数获得的连接区宏观形貌较好,无隧道、孔洞等缺陷;连接区晶粒细化;前进速度为150mm/min时获得的试样其晶粒尺寸较大;各试样抗拉强度最高可达到母材的90.92%,拉伸断口位于热影响区,断裂方式为韧脆混合断裂;前进速度为200mm/min时获得的试样其自腐蚀电流密度最低,耐腐蚀性能最好。

A friction stir joining experiment was conducted using 4mm thick AZ80M magnesium alloy.The rotation speed of the stirring head was fixed at 1000rpm,and the advancing speeds were set at 150mm/min,200mm/min,and 250mm/min.The microstructure,tensile strength,microhardness,and corrosion resistance of the samples obtained under these parameters were analyzed.The results showed that the joints obtained under these parameters had good macroscopic morphology with no tunnels or holes.There was a refinement of grains in the jointed zone.The sample obtained at an advancing speed of 150mm/min had larger grain size.The highest tensile strength of the samples could reach up to 90.92%of the base material,with the tensile fracture occurring in the heat-affected zone and the fracture mode being a mixture of ductile and brittle fracture.The sample obtained at an advancing speed of 200mm/min had the lowest self-corrosion current density and the best corrosion resistance.