To obtain a sliding material excellent in corrosion resistance to biodegradable oil and having superior conformability to a mating material by specifying respective contents of Sn, Pb, Ni, and Zn in a lead bronze type material.
This sliding material has a composition consisting of, by weight, 9.0-15.0% Sn, 8.5-11.0% Pb, ≤3% Ni, 3.0-10.0% Zn, and the balance Cu. In this composition, Sn content in the amount not lower than the lower limit is necessary to strengthen the crystallization of Cu and also Sn content is regulated to a value not higher than the upper limit in order to allow Sn to enter into solid solution perfectly in Cu. Although it is necessary to regulate Pb content to a value not lower than the lower limit to secure machinability, Pb is regulated to a value not higher than the upper limit because Pb is liable to lower strength (hardness) with the increase of its content. Zn is necessary to improve corrosion resistance, and the effect becomes remarkable when Zn content is not lower than the lower limit, and, when it exceeds the upper limit, Zn is liable to be zinc oxide and the probability of occurrence of material defects is increased. Although Ni can prevent the segregation of Pb and contribute to the improvement of strength, hardness is increased and conformability to a mating material is reduced when its content exceeds the upper limit.
SAITO HIDEAKI
ISHIKAWA KATSUJI
OKAWA SATOSHI
KONISHI MITSUKO
