Influence of B4C/BN on solid particle erosion of Al6061 metal matrix hybrid composites fabricated through powder metallurgy technique

Abstract This work investigates and elucidates the influence of B4C and BN reinforcements on the solid particle erosion behavior of Al6061/B4C/BN metal matrix hybrid composites fabricated through the powder metallurgy technique. The metal matrix hybrid composites with reinforcement content of (2, 4, 6, and 8 wt %) B4C, and 2 wt% BN was fabricated by compacting the mechanically alloyed powders within closed circular cavity compaction die at 800 MPa pressure and subsequently sintering them at 600 °C for 3 h. The morphology of milled powders and surface profiles of samples before and after erosion were examined by X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy, elemental mapping, and surface roughness tester. The composites showed a maximum compressive strength of 249 MPa and maximum hardness of 184HV. To determine the erosion rate, various control parameters like reinforcement content, erodent velocity, erodent discharge rate and angle of impingement were considered. Taguchi's L16 (44) orthogonal array-based design of experiments was used to govern the optimum parameter settings, which led to the minimization of the erosion rate. Further, for obtaining the best response from solid particle erosion trails, the whole process was analyzed by multiple linear regression model to establish a relationship between the input and output parameters. Finally, nature-inspired, robust evolutionary strategy antlion optimization (ALO) was used for finding out the optimal parameters for the minimum erosion rate, which were found out to be 8 wt % B4C reinforcement, 80 ms−1 erodent velocity, 8 gmin-1 erodent discharge rate and 45° angle of impingement. Among all the parameters used for the erosion test, impact velocity is the most significant factor in determining the erosion rate.