Enhancement of mechanical properties of thermite heat assisted friction stir welded aluminium bronze alloy (C95300) by eliminating tunnel defect

Thermite Heat-Assisted Friction Stir Welding (THAFSW) is recognized as an efficient welding method for joining aluminium bronze (AB) alloys. The mechanical and metallurgical characteristics of the welded joints were analyzed and compared with those fabricated using the conventional friction stir welding (CFSW) technique. Tensile strength and hardness assessments of the welded specimens were conducted at ambient temperature. The findings revealed that the THAFSW joints exhibited superior mechanical properties, with tensile strength and elongation improving by 11 % and 25 %, respectively, compared to joints produced through the conventional approach. The strengthening mechanism of the welded joints was examined based on images captured through macroscopy, optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The THAFSW process effectively eliminated tunnel defects and facilitated the development of a uniform α-phase microstructure, which contributed to enhanced mechanical performance.