(辽宁出入境检验检疫局，大连 116001)
摘 要: 采用OPM、SEM及EDS等检测手段研究C89320无铅铋青铜宏观、微观组织特征及力学性能。结果表明：该合金以连铸方式生产，显微组织由α相、富磷α相、粒状金属铋和Cu3P组成。粒状金属铋和Cu3P只在富磷α相内生成，其分布、形态、数量和大小与富磷α相成分有关。铸态下，该合金的屈服强度为148 MPa、抗拉强度为300 MPa、断后伸长率为36.5%、硬度为70.5 HBW、抗压强度为146 MPa、夏比冲击吸收能量为28 J。常温冲击断口呈韧窝状，具有良好的切削加工性能。
关键字: C89320无铅铋青铜；Bi；Cu3P；富磷α相；力学性能
（Entry-Exit Inspection and Quarantine Bureau of Liaoning Province, Dalian 116001, China）
Abstract:The macrostructure, microstructure and mechanical properties of C89320 lead-free bismuth tin bronze were investigated by OPM, SEM and EDS techniques. The results show that when the C89320 is fabricated by continuous casting process, the microstructure mainly contains α phase, phosphorus-rich α phase, particle-like Bi and Cu3P phases. Bi and Cu3P phases are associated with the phosphorus-rich α phase, whose morphology, size and number are related to the composition of the phosphorus-rich α phase. The yield strength, tensile strength, elongation, hardness, compressive strength and impact energy of the as-cast alloy are 148 MPa, 300 MPa, 36.5%, 70.5 HBW, 146 MPa, and 28 J, respectively. The impact fracture at the room temperature is typical dimple fracture pattern and the alloy has excellent cutting machinability.
Key words: C89320 lead-free bismuth tin bronze; Bi; Cu3P; phosphorus-rich α phase; mechanical properties
