An investigation on mechanical tribological and machining characteristics of aa7075 reinforced with boron carbide and titanium diboride

Abstract

Metal Matrix Composites (MMCs) have emerged as promising materials in various industrial applications due to their desirable properties such as high strength, lightweight, and excellent wear resistance. Among MMCs, aluminium-based composites have garnered significant attention owing to the widespread use of aluminium in industries such as automotive and aerospace. This study focuses on investigating the effects of incorporating hybrid fillers, Boron Carbide (B4C) and Titanium Diboride (TiB2), on the properties of AA7075 aluminium alloy using the ex-situ stir casting method. The main objectives are to assess the morphological, mechanical, tribological, and machinability characteristics of the developed composites. The fabrication process involved varying the B4C content while keeping TiB2 constant at 3 wt. %. Morphological studies revealed a uniform dispersion of fillers within the matrix, confirming successful fabrication. Mechanical testing according to ASTM standards included tensile strength, compression strength, impact strength, hardness, and density evaluation. Results showed that the AA7075/9 wt. % B4C/3 wt. % TiB2 composite exhibited superior properties compared to the base alloy. Specifically, the maximum hardness attained was 76 BHN, compressive strength reached 231 MPa, and tensile strength achieved 236 MPa, representing increases of up to 43%, 9%, and 19%, respectively, compared to the base alloy. This enhancement in mechanical properties can be attributed to the effective reinforcement and fine dispersion of B4C and TiB2 particles within the aluminium matrix. newline