【摘要】 对10mm厚LF2铝合金搅拌摩擦焊接进行了研究。结果表明:焊接厚板时,为防止出现隧道型缺陷,须在较低的焊速和转速下进行。当焊速为9mm/min,转速为950r/min,焊接输入能量为6230W时,接头强度值最高,其值与母材强度值相等。接头处由平均尺寸约为15μm的均匀细小的晶粒组成;热影响区平均晶粒尺寸较大,其最大值约为28μm;热机械影响区内组织细长,局部区域最大长度可达到85μm。焊核区平均硬度与母材相当,中心最高硬度可达HV95,近缝区硬度低于母材硬度。更多还原

【Abstract】 The welding of 10 mm thick LF2 aluminum alloy in friction stir welding was investigated. The results show that thicker plate should be jointed at lower welding velocity and rotation speed, otherwise there would get the joint with huge tunnel defect. The highest strength joints that are equal to parent metal can be obtained at 9 mm/min of welding velocity, 950 r/min of rotational speed and 6 230 W of input energy, which are regarded as the most ideal parameters under experimental welding conditions. There are the smallest size grains of 15 μm in weld nugget; Heat affected zone are composed of coarse grains and the largest size of heat affected zone microstructure is 28 μm; Thermomechanically affected zone consists of stripy structure which is 85 μm in length in some area. Average microhardness in weld nugget is equal to parent metal’s, the most microhardness is HV95 and lower than parent metal’s in the area near weld nugget .更多还原