Abstract: In order to make the wear-resistance and machinability of the copper-based sliding material, in which such particles as AlN, Al.sub.2 O.sub.3, NiB, Fe.sub.2 B, SiC, TiC, WC, Si.sub.3 N.sub.4, Fe.sub.3 P, Fe.sub.2 P and/or Fe.sub.3 B are dispersed in the matrix consisting of sintered Cu or Cu alloy, the dispersion is performed such that the weight proportion and the average particle diameter of the medium-hardness particles of Hv 500 or more and 1000 or less are greater than those of the high-hardness particles having Hv 1100 or more.

Abstract: A copper alloy material excellent in the resistance to corrosion caused by lubricating oils containing sulfur-based additives. The alloy comprises from over 5 to 50% Ni, 0.1-2% Ag and the balance consisting substantially of Cu, and optionally contains at least one member selected among (1) up to 20% Sn, up to 0.5% P, up to 5% Al, up to 1% Si, up to 5% Mn, up to 30% Zn, up to 10% Fe and/or up to 1% Sb, (2) up to 30% in total of Pb and/or Bi, (3) up to 30% in total of graphite MoS.sub.2. WS.sub.2 and/or BN, (4) up to 20% in total of Al.sub.2 O.sub.3, SiC, SiO.sub.2. Fe.sub.3 P, AlN, Si.sub.3 N.sub.4, TiC, WC, BN, NiB and/or FeB, and (5) 0.001-1% S.