The effect of machining processes on the physical and surface characteristics of AA2024-B4C-SiC hybrid nanocomposites fabricated by hot pressing method

Abstract

In this study, an attempt was made on the AA2024 alloy based hybrid nanocomposites reinforced with different weight percentage of SiC and B4C particles to investigate their physical and machinability characteristics including surface morphology. The Material Removal Rate (MRR), Surface Roughness (SR) of the nanocomposites machined by various machining processes namely Abrasive Water Jet (AWJ) machining, Wire Electrical Discharge (WED) machining and Computer Numerical Controlled (CNC) turning processes were studied comparatively. The machined surface formed by the each machining process is examined and its surface quality was discussed for each hybrid nanocomposite. Results show that the hardness is increased to 101.6 BHN from 179.4 BHN, when 2 wt.% of B4C and SiC particles is added to AA2024 matrix. Observed from the results that the addition of 2 wt.% of B4C and SiC particles produces the highest porosity of 3.36% for nanocomposite samples. The experimental results revealed that the addition of particulates in to the matrix reduces the MRR and increases SR. MRR results showed that hybrid nanocomposites machined by AWJ technique has minimum MRR of 0.0221 mm3/min. The surface roughness of the nanocomposites machined with AWJ process was 3.2 µm and increased to 6.81 µm for the AA2024-B4C-SiC hybrid nanocomposites machined with CNC process.