冷却速率对钴铬钼合金微观组织及力学性能的影响

Effect of Cooling Rate on Microstructure and Mechanical Properties of Cobalt-Chrome-Molybdenum Alloy

钴铬钼合金具有较好的生物相容性及耐磨性,是骨关节植入物用最广泛的金属材料。研究了1 150℃保温2 h后空冷、风冷、水冷、气淬不同冷却速度的热处理工艺对钴铬钼合金材料组织与性能的影响。结果显示:随着冷却速度的提升,钴铬钼合金中的碳化物强化相更为细小、更为弥散地分布于基体中,材料强度及塑性均得到较大幅度提升。在真空条件下1 150℃保温2 h,氩气冷却冷速在150℃/min条件下,材料抗拉强度、屈服强度、伸长率分别达889 MPa、585 MPa、13%。

Cobalt-chromium-molybdenum alloy is the most widely used metallic material for bone and joint implants owing to its outstanding biocompatibility and wear resistance.In this work,the impacts of heat treatment processes with different cooling rates of air cooling,air blast cooling,water cooling,air quenching after treated with the regime of 1150℃for 2 h on the microstructures and mechanical properties of cobalt-Cr-Mo alloys were studied.The results demonstrated that with the increase of cooling rate,the carbide strengthening phases of the Co-Cr-Mo alloys became markedly finer and more dispersive in the matrixes,and both the strength and plasticity of the material were remarkably enhanced.Under the conditions of keeping 1150℃for 2 h in vaccum and the argon cooling rate of 150℃/min,the tensile strength,yield strength and elongation of the specimen reached 889 MPa,585 MPa and 13%,respectively.