Joining phenomena and joint strength of friction welded joint between pure aluminium and low carbon steel

Abstract

This paper describes the joining phenomena and joint strength of friction welded joints between pure aluminium (P-Al) and low carbon steel friction welds. When the joint was made at a friction pressure of 30 MPa with a friction speed of 27?5 s 21 , the upsetting (deformation) occurred at the P-Al base metal. P-Al transferred to the half radius region of the weld interface on the low carbon steel side, and then it transferred toward the entire weld interface. When the joint was made at a friction time of 0?9 s, i.e. just after the initial peak of the friction torque, it had y93% joint efficiency and fractured on the P-Al side. This joint had no intermetallic compound at the weld interface. Then, the joint efficiency slightly decreased with increasing friction time. The joint had a small amount of intermetallic compound at the peripheral region of the weld interface when it was made at a friction time of 2?0 s. When the joint was made at a friction time of 0?9 s, the joint efficiency decreased with increasing forge pressure, and all joints were fractured at the P-Al side. Although the joint by forge pressure of 90 MPa had hardly softened region, it had y83% joint efficiency. To clarify the fact of decreasing joint efficiency, the tensile strength of the P-Al base metal at room temperature was investigated, and the tensile test was carried out after various compression stresses and temperatures. The tensile strength of the P-Al base metal has decreased with increasing compression stress at any temperature. Hence, the fact that the joint did not achieve 100% joint efficiency was due to the decrease in the tensile strength of the P-Al base metal by the Bauschinger effect. To obtain higher joint efficiency and fracture on the P-Al side, the joint should be made without higher forge pressure, and with the friction time at which the friction torque reaches the initial peak.

Joining phenomena and joint strength of friction welded joint between aluminium–magnesium alloy (AA5052) and low carbon steel

“…The authors also presented the tensile strength of friction welded joints between pure Al and low carbon steel (LCS). 27 If combinations of dissimilar materials such as Al alloy and steel can be joined using the same method as that shown in previous reports, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] the joining mechanism will be clarified. In particular, clarifications of the joining mechanism are required concerning the weldability of Al alloys with other metals because an expansion in the use of Al alloys is expected.…”

Joint properties of friction welded joint between pure magnesium and pure aluminium with post-weld heat treatment

“…A high temperature microscope was used for the observation of the IMC interlayer growth at the weld interface, which was recorded continuously using digital video. The detailed method of this in situ observation has been described in previous reports [20,24].…”

“…In previous works, some of the authors were investigated as basic research that the effect of friction welding conditions on the mechanical (mainly tensile strength) and metallurgical properties of the joint with various PWHT conditions in addition to as-welded condition up to now for dissimilar joints made by friction welding method as following combinations: pure titanium (Ti) and austenitic stainless steel [19], pure Ti and pure aluminium (Al) [20], pure Ti and Al alloys [21], pure Ti and pure nickel (Ni) [22], Al alloys and low carbon steel (LCS) [23], pure Al and LCS [24], brass and LCS [25], and pure Al and pure Ni [26,27]. From those reports, even though the friction welding process can minimize the generation of IMC interlayer between dissimilar metals, it was estimated that IMC interlayer will be affected to PWHT condition for the joint fracture.…”

Arc Brazing of Aluminium, Aluminium Matrix Composites and Stainless Steel in Dissimilar Joints

“…Hence, different thermal joining techniques with lowered heat input to the joining area or reduced joining times are a permanent object of research and development. Thus, friction welding, spot welding, laser-assisted welding, and brazing processes, as well as hybrid welding processes are suitable techniques to produce resilient dissimilar Al/steel joints [10][11][12][13]. The herein focussed arc brazing represents a cost-efficient alternative to laser-assisted welding and brazing.…”