The Effects Of FSW Process On LD10/LF6 Metal Flowing And Mechanical Properties

Metal flowing is the main course during FSW. And, metal flowing is one of important researching parts of FSW. Knowing the law of metal flowing about FSW best, which helps to forecast joint results and explain the mechanism of FSW, and, which is good for process optimization exactly.Based on the achievements of other experts on FSW, the metal flowing and micro-structural evolution in the FSW of L2-A1 to itself, of L2-A1 to T2-Cu, of T2-Cu to itself and of LF6-A1 alloy to LD10-A1 alloy were studied under different welding conditions. The influences of plunge depth, push angle, profile of tool, rotation speed and welding speed on metal flowing were studied. And the microstucture, tensibility and bendness of FSW joints were studied. The regularity of how processing parameters effect on mechanical property was analyzed.Through the experiments, the research results show that the repeated dynamical recrystallization is the reason for metal keeping flowing. Rotation speed and welding temperature effect on metal plastic flowing both. Keeping welding temperature in a certain range is good for metal dynamical softening, and promoting flowing, then completing welding easily. The tool makes the material keep high speed, which lead to heats it quickly and flowing steady.Welding process parameter has a essential effect on mechanical performance of LD10/LF6 aluminum alloy joint. In the conditions of low rotation speed, raising welding speed improves joint tensile strength; when rotation speed gets higher, changing welding speed is for nothing. When welding speed is low, changing rotation speed does not make joint tensile strength change; by raising welding speed, higher rotation speed is bad for tensile strength. When welding speed and rotation speed are both low, the mechanical properties of joints welded with non-threaded tool are betterthan those come from threaded tool; increasing welding speed and rotation speed does not influence tensile strength. In the certain range, taking welding speed and rotation speed into consideration both, LD10/LF6 aluminum alloy joint welded with threaded tool has the highest ultimate tensile strength of 327.5MPa with Dfsw=56250 (Dfsw=VfswX UfsW; Vfsw=value of welding speed, UfSW= value of rotation speed).