COPPER-BASED SLIDING MEMBER

PROBLEM TO BE SOLVED: To provide a copper-based sliding member that has a low coefficient of static friction with a mating member and is suitable for use in a reciprocating sliding portion.SOLUTION: The sliding layer of said copper-based sliding member comprises an island-shaped copper alloy phase dispersed in the sliding layer in the form of a sea-island structure surrounded by graphite, and in which the ratio of the island-shaped copper alloy phase having a length in the direction parallel to the sliding surface of 25 to 500 μm to the sliding layer is set at 5 to 40 vol%. Thereby, at the time of startup in which the sliding layer is to be loaded, the island-shaped copper alloy phase has its surrounding taken-in by the graphite, and since the sliding occurs at the interface with the graphite, only a slight elastic deformation occurs in the island-shaped copper alloy phase, and the coefficient of static friction with the mating member is lowered.SELECTED DRAWING: Figure 1 【課題】 相手部材との静摩擦係数が低く、往復摺動部での使用に好適な銅系摺動部材を提供する。【解決手段】 摺動層には、黒鉛により取り囲まれた海島構造の形態で摺動層中に分散する島状銅合金相を含み、摺動層に対する摺動面に平行方向の長さが２５〜５００μｍである島状銅合金相の割合を、５〜４０体積％としている。これにより、摺動層に負荷される起動時には、島状銅合金相が周囲を黒鉛により取り込まれており、黒鉛との界面ですべりが発生するので、島状銅合金相には僅かな弾性変形しか生じることがなく、相手部材との静摩擦係数が低くなる。【選択図】 図１