原位纳米颗粒增强铜合金的制备及其强化机制研究
发布时间：2018-08-25 17:14
【摘要】：本文以ZCuSn10Zn2合金为基体合金,通过添加Fe、Co元素,利用离心铸造技术制备出原位纳米颗粒增强ZCuSn10Zn2Fe1.5Co1合金,借助于EDS能谱分析、透射电镜分析等检测手段确定了增强相纳米颗粒为Fe颗粒,颗粒尺寸分布在2-20nm之间,并与Cu基体保持着共格关系,新型合金组织从原合金粗大的树枝晶转变为晶粒尺寸在20-60μm之间的等轴晶,纳米铁颗粒均匀弥散的镶嵌在ZCuSn10Zn2Fe1.5Co1合金的等轴晶粒中,此外合金中Sn元素的偏析现象也得到了减轻。与ZCuSn10Zn2合金相比,ZCuSn10Zn2Fe1.5Co1合金的抗拉强度由原来的225MPa提高到419.75MPa,合金的伸长率保持在15.68%,材料的延塑性得到了很好地保持。 通过一系列的固溶、时效工艺,研究了合金力学性能的变化规律。合金经过700℃固溶两小时后,抗拉强度和断后伸长率分别达到了485.8MPa、51.84%,较铸态合金提高了15.74%、230.62%,再经过400℃时效四小时后,合金的抗拉强度达到了522.37MPa,相比较铸态合金的419.75MPa提高了24.5%,断后伸长率为46.56%,相比较铸态合金的15.68%提高了196.94%。 借助于SEM、TEM、HRTEM、小角X射线散射(SAXS)技术、原位拉伸实验研究了纳米颗粒增强铸造铜合金的强化机理和纳米颗粒在合金铸态和时效态的演变,结果表明铸态合金和时效合金中都分布有大量与基体保持共格或半共格的纳米颗粒。弥散分布的纳米颗粒、晶粒的显著细化及硬脆第二相的减少是合金综合力学性能大幅提高的主要原因。 分析了纳米颗粒在铜合金基体晶粒中均匀分布的原因,发现凝固过程中传统的微米级颗粒与固液界面的交互作用模型并不适用于原位纳米颗粒增强铜合金中纳米铁颗粒与固液界面的交互作用,指出凝固过程中纳米颗粒在合金液中做无规则的布朗运动是纳米颗粒最终进入合金基体晶粒的关键。 把原位纳米颗粒增强技术与精密铸造技术相结合,采用离心铸造制备出长期耐压指标达4.5MPa、短期耐压指标达6.0MPa的ZCuSn10Zn2Fe1.5Co1泵体。
[Abstract]:In this paper, the in-situ nano-particle reinforced ZCuSn10Zn2Fe1.5Co1 alloy was prepared by centrifugal casting with ZCuSn10Zn2 alloy as base alloy and Fe,Co element added. The results were analyzed by EDS spectroscopy. Transmission electron microscopy (TEM) analysis and other testing methods confirmed that the reinforced phase nanoparticles were Fe particles, the particle size was distributed between 2-20nm and the Cu matrix, and maintained a coherent relationship with the matrix. The new alloy structure changed from coarse dendrite to equiaxed crystal with grain size of 20-60 渭 m. The nano-iron particles were uniformly dispersed in the equiaxed grains of ZCuSn10Zn2Fe1.5Co1 alloy, and the segregation of Sn elements in the alloy was also reduced. Compared with the ZCuSn10Zn2 alloy, the tensile strength of ZCuSn10Zn2Fe1.5Co1 alloy was increased from the original 225MPa to 419.75MPa, the elongation of the alloy was kept at 15.68 and the ductility of the alloy was kept well. The mechanical properties of the alloy were studied by a series of solid solution and aging processes. After two hours of solution at 700 鈩，
本文编号：2203564
[Abstract]:In this paper, the in-situ nano-particle reinforced ZCuSn10Zn2Fe1.5Co1 alloy was prepared by centrifugal casting with ZCuSn10Zn2 alloy as base alloy and Fe,Co element added. The results were analyzed by EDS spectroscopy. Transmission electron microscopy (TEM) analysis and other testing methods confirmed that the reinforced phase nanoparticles were Fe particles, the particle size was distributed between 2-20nm and the Cu matrix, and maintained a coherent relationship with the matrix. The new alloy structure changed from coarse dendrite to equiaxed crystal with grain size of 20-60 渭 m. The nano-iron particles were uniformly dispersed in the equiaxed grains of ZCuSn10Zn2Fe1.5Co1 alloy, and the segregation of Sn elements in the alloy was also reduced. Compared with the ZCuSn10Zn2 alloy, the tensile strength of ZCuSn10Zn2Fe1.5Co1 alloy was increased from the original 225MPa to 419.75MPa, the elongation of the alloy was kept at 15.68 and the ductility of the alloy was kept well. The mechanical properties of the alloy were studied by a series of solid solution and aging processes. After two hours of solution at 700 鈩，
本文编号：2203564
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