Pathway to lead-free brass by stabilizing graphite via TiC-β phase interface

To replace hazardous lead in brass, this study presents a novel casting technique using an integrated electromagnetic-heat field to fabricate a high-performance, lead-free graphite-brass. Conventional casting is challenged by graphite poor wettability and flotation. The new method overcomes this by creating a "graphite-β phase" structure, where graphite is anchored within the body-centered cubic (BCC) β-phase of the brass matrix. This stabilization is achieved via a TiC-mediated mechanism: Ti additives react in situ with graphite, forming lamellar TiC that bridges the graphite and the β-phase, a process facilitated by the crystallographic compatibility between Ti and β-brass. The alloy demonstrates superior machinability, enhanced hardness, and good electrical conductivity, offering a viable pathway for producing eco-friendly, free-machining brass. • 1.Lamellar TiC bridges β–phase brass and graphite, suppressing graphite floating. • 2.A new smelting method bases on electromagnetic–heat field is proposed. • 3.The added graphite in brass as aspect ratio of length to width is 4.0–3.3: 1.