Exfoliation corrosion susceptibility on friction stir welded aluminium 6061/Cr₂O₃ composite

Abstract

The current study investigates the exfoliation corrosion behavior of friction stir welded aluminum composite. The stir casting method was employed to fabricate chromium oxide (2 and 4% wt) reinforced Al 6061 composites. The fabricated composite samples are friction stir welded with two process parameters. The solution immersion tests were performed for two intervals per the ASTM G34 (24 hours, 48 hours), and the weight loss method was employed. The corrosion sample is analyzed by optical microscope FESEM and surface roughness. The gelatinous corrosion product formed over the surface can apply pressure over the grains resulting in the formation of pits. The intergranular corrosion (IGC) is formed by continuous penetration of the solution and the pits. The grains suffering from IGC are more susceptible to pit. The weight-loss method is not sufficient to predict the damage induced by the exco solution. Evaluating the pit depth can help to know the severity of corrosion. The measurement of the pit is difficult due to its irregular nature. The surface roughness instrument is used, and the damage is represented in average roughness (Ra) and average depth (Rz). The exposure duration and welding parameters play a significant role in corrosion. More material is lost at higher process parameters and extended hours of the test, forming higher surface deterioration.

Revolutionizing Aluminum Composite Manufacturing: Harnessing Cr2O3 Reinforcement via Friction Stir Technique

“…Aluminum composites, also known as aluminum matrix composites (AMCs), are engineered materials consisting of aluminum as the matrix reinforced with another material, such as ceramics or carbon fibers. These composites offer a unique combination of properties that surpass those of conventional aluminum alloys, making them desirable for numerous high-performance applications [11][12][13].One of the key advantages of aluminum composites is their enhanced strength-to-weight ratio compared to pure aluminum. By incorporating reinforcing materials, AMCs can withstand higher mechanical loads while maintaining a low overall weight.…”

Influence of tool pin profile on the mechanical strength and surface roughness of AA6061-T6 overlap joint friction stir welding

“…In the conventional welding process, high temperature is significantly developed, which causes changes in the metallurgical characteristics and affects the welded joints' strength. On the contrary, FSW showed significantly minimum deformation driven by mechanical and thermal stresses because the base metal's melting point is higher than the welding temperature [5,6]. Due to FSW's apparent low processing temperature, several welding imperfections such as deformation, solidification cracking, blowholes, spatters, and porosity can be reduced as an advantage to increase weld quality and joint quality [7,8].…”