The main purpose of this work is to establish high cyclic fatigue behaviour of sound welds of aluminium alloys of Al-Mg-Li and Al-Cu-Li doping system under constant and variable amplitude loading. Sound welds of thin sheet (1.8 and 2.0 mm) aluminium-lithium alloys 1420 and 1460 were produced by tungsten inert gas (TIG) and friction stir welding (FSW) technologies. Microstructure investigations, hardness and residual stress measurements, tensile and fatigue tests of welds were performed. It is shown that FSW joints have fine grain microstructure in weld nugget with homogeneous disoriented structure and elongation and deviation of grains in a direction of plasticized metal movement, taken place in adjacent areas. Hardness on joints face was measured, showing areas of softening near the weld. Lower temperature of welded edges heating reduces the maximum level of longitudinal residual tensile stresses in FSW joints in comparison with TIG welds. Tensile strengths of TIG and FSW joints were obtained. The high cycle fatigue tests of FSW and TIG joints under constant and variable amplitude loading were performed. It is shown that fatigue behaviour of FSW joints exceeds the characteristics of the joints obtained by TIG welding.

这项工作的主要目的是在恒定和可变振幅载荷下建立Al-Mg-Li和Al-Cu-Li掺杂系统的铝合金的声焊缝的高循环疲劳行为。薄板（1.8和2.0毫米）铝锂合金1420和1460的声音焊缝是通过钨极惰性气体（TIG）和搅拌摩擦焊（FSW）技术制成的。进行了显微组织研究，硬度和残余应力测量，焊缝拉伸和疲劳测试。结果表明，FSW接头在熔核中具有细小的晶粒组织，具有均匀的错位结构，并且在相邻区域发生了沿塑化金属运动方向的晶粒的伸长和偏离。测量了接头表面的硬度，显示了焊缝附近的软化区域。与TIG焊相比，较低的焊接边缘温度降低了FSW接头中纵向残余拉应力的最大水平。获得了TIG和FSW接头的拉伸强度。在恒定和可变振幅载荷下，对FSW和TIG接头进行了高周疲劳测试。结果表明，FSW接头的疲劳性能超过了TIG焊接获得的接头的特性。