烧结温度对CNTs/Cu复合材料组织和力学性能的影响
Effects of Sintering Temperature on Microstructure and Mechanical Properties of CNTs/Cu Composite
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摘要: 采用电泳沉积法在铜箔上沉积碳纳米管,层层堆叠后在不同烧结温度(550,650,750,850,950 ℃)下热压烧结制备碳纳米管增强铜基(CNTs/Cu)复合材料,研究了烧结温度对复合材料显微组织和力学性能的影响。结果表明:随着烧结温度升高,复合材料中孔隙的数量减少,尺寸减小,碳纳米管分布均匀性增大,铜晶粒尺寸增大,退火孪晶晶粒尺寸增大但数量减少;随着烧结温度升高,复合材料的抗拉强度和显微硬度均呈先减小后增大的趋势,断后伸长率变化呈非单调性变化;当烧结温度为650 ℃时,复合材料的抗拉强度和显微硬度适中,断后伸长率最大,综合力学性能最好。Abstract: Carbon nanotubes were deposited on copper foil by electrophoretic deposition. After stacking and hot pressing sintering at different temperatures (550, 650, 750, 850, 950 ℃), carbon nanotubes reinforced copper matrix (CNTs/Cu) composite was prepared. The effects of sintering temperature on the microstructure and mechanical properties of the composite were studied. The results show that with the increase of sintering temperature, the number and size of pores in the composite decreased, the distribution uniformity of carbon nanotubes increased, the grain size of copper and the annealing twins increased, but the number of the annealing twins decreased. With the increase of sintering temperature, the tensile strength and microhardness of the composite decreased first and then increased, and the change of percentage elongation after fracture was non-monotonic. When the sintering temperature was 650 ℃, the tensile strength and microhardness of the composite were moderate, and the percentage elongation after fracture was the highest; the comprehensive mechanical properties were the best.