【作者】 吴杰；

【导师】 戴挺； 孙飞；

【作者基本信息】 东南大学 ， 材料工程（专业学位）， 2017， 硕士

【摘要】 SiC颗粒增强铜基复合材料具有优良的力学性能、较高的耐磨性和良好的导热性。因此,作为基础材料在工业中有着广阔的应用前景。本文首先采用粉末冶金法制备SiC颗粒增强铜基复合材料,具体研究为:(1)在粒度为5μm的SiC颗粒上进行表面镀镍,镀镍液的PH值在10,水浴温度在40℃时,SiC颗粒表面能够均匀的被镍层包覆。(2)经球磨、SPS烧结后,基体中的SiC颗粒无团聚的现象。SiC颗粒能抑制基体晶粒长大,使晶粒得到细化,其中镀镍SiC颗粒效果较明显,提高铜基复合材料的硬度和抗拉强度。但是加入SiC颗粒后使基体孔隙率变大、延伸率变小。(3)在复合材料中,SiC颗粒具有良好的抗磨效果,铜合金基体中加入SiC颗粒后,能够明显降低复合材料的磨损质量。由于镀镍SiC颗粒与基体界面结合良好,镀镍SiC颗粒增强铜基复合材料磨损表面的划痕比较整齐,镀镍SiC颗粒比未镀镍SiC颗粒的磨损量更小。在粉末冶金法制备基础上,通过半固态搅拌连续铸造法制备SiC颗粒增强铜基复合材料。具体研究为:(1)改进原有连铸设备,包括:炉体、石墨坩埚、结晶器、感应加热线圈、搅拌装置以及循环水路。(2)使用改进后连铸设备,顺利制得连铸棒材。得到最佳半固态铸造工艺参数为.:搅拌速度为400r/min,拉拔温度为1045℃,拉速为20mm/min。(3)在半固态铸造试样中,当加入SiC颗粒后,半固态复合材料的抗拉强度从400MP提高到497MPa,复合材料的断裂方式主要为韧性断裂。更多还原

【Abstract】 SiC particles reinforced copper matrix composites have many favored properties,such as good mechanical properties,superior wear-resistance and good electrical/thermal conductivity.Therefore,as basic industrial materials,they will be widely used in industry.In this paper,copper matrix composites reinforced by SiC particles were prepared by power metallurgy method firstly.The main contents are as follows:(1)Nickel coatings were obtained on the surface of SiC particles by chemical plating method.When the PH=5,bath temperature 40 ℃,the surface of the SiC particles can be coated uniformly.(2)After ball milling and SPS sintering,SiC particles have no signs of agglomeration in copper matrix composites.The SiC particles also can inhibit grain growth,in which the nickel plated SiC particles can significantly refine grains,The Hardness and tensile strength of copper matrix composites reinforced by SiC particles are improved,but the porosity increased and the elongation decreased.(3)The SiC particles have good wear-resistance properties,the wear quality of copper matrix composites can be reduced significantly with addition of SiC particles.Due to the nickel plated SiC particles are smoothly combined with the matrix,scratchs of the copper matrix composites reinforced by nickel plated SiC particles on wear surface are very neat.This paper also explored the equipment and processes of semi-solid stirring continuous casting technology to prepare copper matrix composites reinforced by SiC particles.The main contents are as follow:(1)The original casting equipment was improved gradually including:furnace body,graphite crucible,crystallizer,induction heating coil,stirring equipment and circulating water.(2)Using the modified continuous casting equipment,the continuous casting samples were successfully fabricated.The optimal parameters of the semi-solid casting technology:the speed of stirring at 400r/min,drawing temperature is 1045 ℃ and drawing speed is 20 mm/min.(3)In the addition of SiC particles semi-solid casting samples,tensile strength of copper matrix composites increased from 400 MPa,which is from without SiC particles samples,to 497 MPa,the fracture mode of copper matrix composites is mainly ductile fracture.更多还原