Assessment of induced residual stresses and microstructure of Al/B4C/FA composite extruded by equal channel angular pressing

This research evaluates the residual stresses and microstructure of rods fabricated from a hybrid aluminum matrix composite (Al1050/B 4 C/FA).The rod composite is subjected to various passes (cycles) using equal channel angular pressing (ECAP) at room temperature.Channel angles of 120 and 135 with pass numbers of 1P, 2P, 3P, 4P, 5P, and 6P are used to investigate the induced residual stresses (IRS) and examine the microstructure.The destructive cutting technique (CT) is employed to assess the state of IRS in the axial direction, and scanning electron microscopy (SEM) is used to check the microstructure before and after severe plastic deformation (SPD).The results show that the values of residual stresses tend to increase due to the effects of SPD compared to the casting composite.As the ECAP cycles increase, the magnitudes of residual stresses start to change; the compressive state of residual stresses is near the rod surface, while the stresses are in tensile state near the center of the composite rod.The cycles of ECAP significantly impact the grain size reduction.The smallest grain size is observed at a die angle of 120 after 6 ECAP passes, measuring between 1 and 8 m, while the grain size for the casted rods ranged from 4 to 15 m.