Synthesis and machinability assessment of reinforced Ti6Al4V metal matrix composites

Abstract

Titanium metal matrix composites (TiMMCs) offer exceptional specific strength and thermal stability; however, their machinability is severely hindered by abrasive ceramic reinforcements. The aim of this study synthesizes Ti6Al4V-based TiMMCs reinforced with hybrid B 4 C, ZrO 2 , SiC, and MoS 2 particles via powder metallurgy and optimizes multi-stage machinability through sequential chemical etching, grinding, and polishing, evaluating effects on surface roughness (Ra) and material removal rate (MRR) via Taguchi L 9 orthogonal arrays.The result shown as a morphological analysis revealed homogeneous reinforcement distribution, while XRD confirmed in-situ TiC and TiB2 formation via Ti-B 4 C reactions, enhancing mechanical properties. The optimal B3 composition (7.5 wt.% B 4 C, 12.5 wt.% ZrO2, 7.5 wt.% SiC, 4 wt.% MoS 2 , balance Ti6Al4V) achieved 99.11% relative density, 659 HBNmicrohardness compared to base matrix Ti6Al4V 379 HBN microhardness, and 2964 MPa compressive strength compared to base matrix Ti6Al4V 970 MPa comprehensive strength. Taguchi L 9 optimization identified A 1 B 2 C 3 D 3 for maximum MRR (0.47 gm/min grinding) and A 1 B 1 C 1 D 3 for minimum Ra (0.76 µm post-polishing), highlighting efficiency-quality trade-offs, with grinding most effective for stock removal. This study validates a manufacturing protocol that balances superior mechanical properties of hybrid TiMMCs with precise machinability, enabling their use in demanding engineering applications.