Synergistic effect of hybrid nano-particles reinforced Al7150 metal matrix composites (A17150-hBN-B 4 C) for advanced aerospace applications

The performance of a hybrid metal matrix (HMM) composites relies on the dispersion of reinforcements. The present investigation presents a novel processing technique to fabricate high-performance Al7150 alloy with an even dispersion of hybrid nano-particulates. During the fabrication process, nano-sized reinforcements, boron carbide (B 4 C) and hexagonal boron nitride (hBN) were dispersed uniformly in Al7150 melt with the help of ultrasonic assisted stir casting method. Investigations were carried out to study the influence of hybrid nano-particulates weight percentage (wt.%) on the composite performance by varying it from 0 to 2 at an increment of 0.5 and with an equal reinforcement quantity. Phase identification and microstructural analysis were studied using XRD, EDX, OM and SEM, respectively. Microstructural investigations reveal the homogeneous dispersion of nano-particulates and grain refinement in the hybrid composites. XRD and EDX confirm the existence of the hBN, B4C and Al7150 elements in the hybrid composites. Further, mechanical testing was carried out using UTS for strength evaluation, fracture mechanism and hardness using a micro-hardness tester. Significant improvement in mechanical characteristics was noticed in the as-cast condition. Al7150-1.5% hybrid (B4C-hBN) nanocomposite revealed an 82.03% reduction in porosity, 25.4% enhancement in micro-hardness and 104.25% in tensile strength.