Enhanced milling performance and mechanical properties of B319/TiC composites via hot pressing

Abstract

This study investigates the mechanical and machinability properties of B319 aluminum alloy reinforced with titanium carbide (TiC). Composite specimens containing 5 wt% and 10 wt% TiC were fabricated using high-energy ball milling followed by hot pressing. The effects of TiC reinforcement on densification, microstructure, hardness, transverse rupture strength (TRS), and dry milling behavior were systematically evaluated. SEM/EDS analyses confirmed a uniform dispersion of TiC with strong interfacial bonding. The addition of 10 wt% TiC increased hardness by about 22% and TRS by approximately 10% compared to unreinforced B319, while fractography revealed a transition from ductile to brittle fracture with increasing reinforcement. Machining tests at cutting speeds of 100–300 m/min and feeds of 0.10–0.15 mm/rev showed that TiC addition improved surface finish (Ra < 0.8 µm at 300 m/min) but also increased tool wear (up to 0.84 mm), cutting forces (120–142 N), and specific cutting energy (about four times higher than unreinforced B319). Post-machining observations confirmed material transfer and oxidation at the tool–workpiece interface. Overall, the results indicated that TiC reinforcement enhances strength and surface quality but raises machining costs. In this context, the study contributes to the limited literature by providing an integrated assessment of process–structure–property–machinability relationships for B319/TiC composites.