The Effect of Welding Current and Electrode Force on the Heat Input, Weld Diameter, and Physical and Mechanical Properties of SS316L/Ti6Al4V Dissimilar Resistance Spot Welding with Aluminum Interlayer

Welding parameters obviously determine the joint quality during the resistance spot welding process. This study aimed to investigate the effect of welding current and electrode force on the heat input and the physical and mechanical properties of a SS316L and Ti6Al4V joint with an aluminum interlayer. The weld current values used in this study were 11, 12, and 13 kA, while the electrode force values were 3, 4, and 5 kN. Welding time and holding time remained constant at 30 cycles. The study revealed that, as the welding current and electrode force increased, the generated heat input increased significantly. The highest tensile-shear load was recorded at 8.71 kN using 11 kA of weld current and 3 kN of electrode force. The physical properties examined the formation of a brittle fracture and several weld defects on the high current welded joint. The increase in weld current also increased the weld diameter. The microstructure analysis revealed no phase transformation on the SS316L interface; instead, the significant grain growth occurred. The phase transformation has occurred on the Ti6Al4V interface. The intermetallic compound layer was also investigated in detail using the EDX (Energy Dispersive X-Ray) and XRD (X-Ray Diffraction) analyses. It was also found that both stainless steel and titanium alloy have their own fusion zone, which is indicated by the highest microhardness value.

Investigation and Joint effect Analysis of Ti-6AL-4V & SS-304L in Aerospace Applications

The friction welding basic principle is connecting two materials with the help of friction generated between them using pressure and frictional time. The material used for this is Ti-6AL-4V & SS-304L with aluminum interlayers. The mechanical and metallurgical experimental strengths are investigated successfully. Titanium and stainless steel joined materials are commonly used for different aerospace, chemical, automotive and nuclear applications. The primary investigation of this present work is the connection between titanium and stainless steel with an aluminum interlayer. Initially, stainless steel and aluminum joints were made, and then the aluminum other surface was connected with titanium alloy. Joined welded samples are analyzed with scanning electron microscopes. Welded joint strength and characteristics were determined with the help of the tensile test, micro hardness and impact test. These investigation results were studied and compared with previous experimental studies.

Diffusion Bonding of 1420 Al–Li Alloy Assisted by Pure Aluminum Foil as Interlayer

The Al–Li alloy is becoming popular for aerospace application owing to their low density, high specific strength, good corrosion resistance, etc. The diffusion bonding/superplastic forming (DB/SPF) structure of titanium alloy has been widely used in the aerospace industry. In order to broaden the application of Al–Li alloy, it is necessary to develop its diffusion bonding and superplastic forming (DB/SPF) technology. In the present study, diffusion bonding of 1420 Al–Li alloy assisted by pure aluminum foil was conducted on Gleeble-3500 thermal simulation system under different bonding parameters, the results show that the bonding temperatures have direct influence on the interface microstructure and bond strength of joints. Meanwhile, when the pure aluminum interlayer was introduced into the diffusion bonding process, the alloying element diffusion across the bond can improve the interface integrity and the mechanical properties. The joint formation mechanism with interlayer was investigated in detail, the development and application of this method was explored.