Optimization of Microstructure, Mechanical Properties, and Wear Resistance of Cu ₄₅ Mn ₈ Ni ₃₀ Co ₁₀ Sn ₇ High‐Entropy Bronze Alloy Through Solution‐Aging Treatment

A novel Cu 45 Mn 8 Ni 30 Co 10 Sn 7 high‐entropy bronze alloy is fabricated via induction melting, followed by solution‐aging treatment. The microstructural and mechanical evolution of the alloy during solution‐aging treatment is systematically investigated. Additionally, the tribological behavior of the as‐treated alloy is examined from 25 °C to 400 °C. The results demonstrate that solution treatment alleviates elemental microsegregation and dissolves the discontinuous lamellar structure, whereas aging treatment triggers the reprecipitation of the Ni 2 MnSn phase from the α‐Cu solid solution matrix. The as‐treated alloy demonstrates remarkable hardening and superior strength‐toughness synergy compared to the as‐cast state, with a hardness of 420 HV, a yield strength of 926 MPa, and a fracture toughness of 22.8 MPa m 1/2 . The friction and wear performance of the as‐treated alloy is sensitive to high‐temperature oxidation. The average friction coefficient of the as‐treated alloy monotonically decreases from 0.72 at 25 °C to 0.53 at 400 °C, which is attributed to the formation of a friction‐reducing metal oxide tribolayer in the worn surfaces starting from 200 °C. Meanwhile, distinct oxidative wear occurs with increasing temperature, leading to a rapid increase in the wear rate from 1.12 × 10 −5 mm 3 N −1 m −1 at 25 °C to 12.5 × 10 −5 mm 3 N −1 m −1 at 400 °C.