新型耐高压铸造锡青铜的研制

Development of Novel Pressure-resistance Tin-bronze

以ZCuSn3Zn8Pb6Ni1合金为基础,通过添加Fe和Co,开发了耐高压铸造ZCuSn3Zn8Pb6Ni1FeCo合金,研究了Fe和Co对合金组织和性能的影响。结果表明,ZCuSn3Zn8Pb6Ni1FeCo合金显微组织与ZCuSn3Zn8Pb6Ni1的相同之处在于均以α-{Cu,Sn,Zn}为基体,存在硬脆相δ-Cu10Sn3,Pb以单质形式析出;ZCuSn3Zn8Pb6Ni1FeCo合金中还存在α-Fe和γ-Fe析出相,以及CoCu2Sn、Fe3Co7、Fe4Zn9等硬质相,这些硬质相和基体之间为共格或半共格关系;ZCuSn3Zn8Pb6Ni1合金铸造组织为典型的枝晶组织,晶粒平均直径约3mm,抗拉强度为180～230MPa,而ZCuSn3Zn8Pb6Ni1FeCo合金为等轴晶组织,晶粒平均直径为20～60μm,抗拉强度为400～450MPa,伸长率在20%以上;ZCuSn3Zn8Pb6Ni1FeCo合金消除了明显存在于ZCuSn3Zn8Pb6Ni1合金中的Sn的宏观偏析。

Pressure-resistant cast ZCuSn3Zn8Pb6Ni1FeCo alloy was developed by adding Fe and Co into ZCuSn3Zn8Pb6Ni1 matrix alloy,and effects of Fe and Co element on microstructure and properties of the alloy were investigated.The results reveal that,compared with that of ZCuSn3Zn8Pb6Ni1 matrix alloy,the microstructure of ZCuSn3Zn8Pb6Ni1FeCo alloy is basically composed of α-{Cu,Sn,Zn}phase and hard-brittle δ-Cu10Sn3 phase as well as single Pb precipitates also.In addition,there exist α-Fe phase and γ-Fe precipitates and CoCu2Sn,Fe3Co7,Fe4Zn9 strengthening phase which exhibits semi-coherent or coherent lattice orientation with the matrix in the ZCuSn3Zn8Pb6Ni1FeCo alloy.ZCuSn3Zn8Pb6Ni1 matrix alloy exhibits typical dendrite with average grain size of approximately 3 mm and tensile strength of 180～230 MPa,while ZCuSn3Zn8Pb6Ni1FeCo alloy exhibits equiaxed structure with average grain size of 20～60 μm and tensile strength of 400～450 MPa as well as elongation more than 20%.The macro-segregation of Tin which exists in CuSn3Zn8Pb6Ni1 matrix alloy is eliminated in the ZCuSn3Zn8Pb6Ni1FeCo alloy.