Abstract: To provide a bronze alloy and a sliding member, to which high seizure resistance and high adhesive wear resistance against fluctuating high speed/high surface pressure sliding are imparted, while having a lead-free composition. A bronze alloy of the present application characteristically contains 8 to 15 mass % of Sn, 0.5 to 7.0 mass % of Bi, 0.5 to 5.0 mass % of Ni, 0.08 to 1.2 mass % of S, 0.5 to 6.0 mass % of Fe, and a balance of Cu and inevitable impurities; and the bronze alloy has a eutectoid structure in which a fine flaky copper-tin-based intermetallic compound precipitates in the ?-copper matrix and also an iron-nickel-based intermetallic compound and a copper-iron-based sulfide complex are dispersed.

Abstract: A bronze alloy includes copper, tin, bismuth, nickel and sulfur and a metal structure of the bronze alloy has an eutectoid phase including ?-copper having a lamellar structure including a flaky copper-tin intermetallic compound precipitated and metal particles including the bismuth dispersedly precipitated therein.

Abstract: A bronze alloy having a metallographic structure which has a fine multilayer structure constituted of a layer of ?-form copper and a layer of a copper-tin intermetallic compound and includes an eutectoid phase comprising, dispersedly precipitated therein, fine metal grains containing at least bismuth (fine bismuth grains, etc.). The proportion of the lamellar eutectoid phase is 10-70% by area. From the standpoint of composition, the bronze alloy comprises copper and tin as main components and contains nickel, bismuth, and sulfur as additive elements, the nickel content being 0.5-5.0 mass %, the bismuth content being 0.5-7.0 mass %, and the sulfur content being 0.08-1.2 mass %. The tin content preferably is 8-15 mass %. The alloy may further contain lead in a proportion of 4 mass % or lower. The bronze alloy is used as a sliding surface of a sliding member (e.g., a hydraulic cylinder block).