Effect of laser parameters on microstructural evaluation and wear properties of A713–Al ₂ O ₃ –CaCO ₃ hybrid composite processed by laser surface melting

Abstract The microstructural and wear behaviour of the stir cast A713–15wt-%Al 2 O 3 –5wt-%CaCO 3 aluminium hybrid composite processed using laser surface melting process was investigated. The A713 matrix reinforced with Al 2 O 3 and CaCO 3 was initially fabricated using stir casting process. The effects of laser beam power and scanning speed on the microstructure, hardness, and wear behaviour were studied in samples processed at a constant energy density. The investigation revealed superior wear resistance, with wear loss was reduced by 42% than that of as–cast A713–15wt-%Al 2 O 3 –5wt-%CaCO 3 aluminium hybrid composite. The maximum micro hardness of the laser treated sample was increased from 44 HV to 164 HV, which is 3.7 times than that of substrate material. As a results, wear rate was substantially reduced from 3.8 × 10 −3 mm 3 m −1 to 1.2 × 10 −3 mm 3 m −1 . It was observed that shortest interaction time of 0.2 s during laser melting was most effective for achieving optimal grain refinement and improved wear resistance.