Adhesive assisted TiB₂ coating effects on friction stir welded joints

Friction stir welding is a novel technique for joining ferrous and non-ferrous materials in a solid state. The groove fill techniques are most popular and generally used by researchers to dope reinforcement in the FSWed zone to improve the properties of joints. The main drawback of this technique is that a few amounts of reinforcement material come out from the groove during the fabrication of the joint. In the present work, the adhesive-assisted reinforcement technique was used to overcome this problem for the fabrication of particulates reinforced friction stirred weld joint. In the present work, the aluminum alloy plate edges were coated with a thin layer of TiB2. The coated and non-coated edge plates were joined using friction stir welding at the rotational speed of 1400 and 2240 rpm, and welding speed of 32 mm/min using a taper threaded pin tool. The tensile strength of coated edge plate welded joints was found highest in comparison to non-coated joints which was 39.74% superior. The percentage elongation of coated edge joint was observed about 1.5 times lower than the non-coated edge plate joint. The flexure strength of TiB2 reinforced coated edge joint was found about 1.5 times higher. However, the impact strength of coated edge plate was found nearly three times lower than the uncoated edge joints. The TiB2 coated edge joints reveal 22.75% higher hardness than the non-coated edge plate joints welded at the rotational speed of 2240.