Vol.20, No.2, 2020, pp. 99–102
UDC:

AA 2014T3 and AA 5059H11 are two dissimilar aluminium alloys friction stir welded. The joint has been examined in terms of hardness, microstructure, and mechanical properties. The microstructure of the weld area is characterized by using optical microscopy. Seven diverse regions of the microstructure in the joint can be illustrious. It has been noticed that a structure of fine grain is formed in the nugget region as a consequence of recrystallization. The thermomechanically affected and heat affected zones of aluminium alloy 2014 are characterized by the lowest hardness values in spite that there is a general hardness decrease through the weld zone, compared to both base metals. The ultimate tensile strength values of the dissimilar joint are found to be varying between 54 to 66 % those of the base metal. The outcomes display that friction stir welding can be effectively applied for joining dissimilar aluminium alloys.

Keywords: Lagrange variation principle, mathematical model, finite difference method, stress-strain state, matrix sweep method