【作者】 李春月；

【导师】 解念锁；

【作者基本信息】 陕西理工学院 ， 材料加工工程， 2010， 硕士

【摘要】 本研究采用粉末冶金法制备了SiCp/Cu梯度复合材料,借助光学显微镜、扫描电镜、XRD、显微硬度计、涡流电导仪等研究了其显微组织、显微硬度及导电性,探讨了其热疲劳性能、氧化性能和磨损性能。研究结果如下:SiCp/Cu梯度复合材料的基体连续,层间界面消失,增强颗粒呈梯度分布;复压烧结工艺使材料的平均致密度与一次烧结后的试样相比提高了7.1%,电导率提高7.8%,压缩变形后,最高致密度达到96.1%;SiCp/Cu复合材料的电导率随着SiC含量的增加而降低,经压缩变形和退火处理后,SiCp/Cu复合材料的电导率有所增加。SiCp/Cu梯度复合材料从基体至表面硬度值逐渐提高,导电性逐渐减小;600℃循环淬水热疲劳实验表明,六层及大于六层的SiCp/Cu梯度复合材料经过80次循环淬水后未出现层间裂纹,表现出良好的抗热疲劳性能。400~700℃的氧化实验表明:SiCp/Cu复合材料的抗氧化性能优于纯Cu;SiC体积分数为20%时和SiC颗粒尺寸为20μm时复合材料的抗氧化性较好;在700℃循环氧化条件下,复合材料的氧化增重呈现出近抛物线变化规律;SiCp/Cu梯度复合材料沿厚度方向的抗氧化性呈现梯度变化特征。SiCp/Cu复合材料的耐磨性随SiC含量的增加而增强。SiCp/Cu梯度复合材料的耐磨性优于纯铜,并且呈梯度分布;低载荷条件下的磨损机制主要是磨粒磨损,载荷较高时,主要是磨粒磨损和剥层磨损的综合作用。更多还原

【Abstract】 SiCp/Cu gradient composites was fabricated by powder metallurgy. The microstructure, hardness and conductivity of SiCp/Cu gradient composites were investigated by optical microscope, scanning electronical microscope, XRD and eddy current conductivity instrument. The thermal fatigue properties, oxidation properties and wear resistance were discussed in this paper. The results are as follows.The matrix of SiCp/Cu gradient composites is continuous, there is no interface between layers, and the distribution law of reinforced particles is gradient. The average density of SiCp/Cu gradient composites is enhanced 7.1% and conductivity is increased 7.8% by re-pressing and re-sintering process. After the compression deformation, the maximum density reached 96.1%. The conductivity of SiCp / Cu composite decreased with the increase of SiC content, and the conductivity increased by compressive deformation and annealing. The hardness of a gradual increase in the conductivity decreased gradually from the matrix to the surface of SiCp/Cu gradient composites. SiCp/Cu gradient composites is repeatedly tested by water quenching with the temperature difference of 600℃, and the results show that six-layered and higher than six-layered SiCp/Cu gradient composites have no crack between layers after 80 cycle water quenching, and have the better thermal fatigue resistance properties.The oxidation experiments show that the oxidation resistance behavior of SiCp/Cu composites is better than Cu between 400℃and 700℃. 20%vol SiCp/Cu composites and with SiC 20μm in size has the better oxidation resistance behavior. With the oxidation time added, the mass gained of the composites added, and showed the same changes in the law of parabola in the cyclic oxidation conditions in 700℃;The oxidation resistance properties of SiCp/Cu gradient composites possess the gradient characteristic along the direction of thickness.The wear resistance properties of SiCp/Cu composites are increasing with the SiC content increasing. The wear resistance of SiCp/Cu gradient composites is superior pure Cu, and the distribution law of wear resistance is gradient.When the applied load is lower, the wear mechanism of SiCp/Cu composites is mainly abrasive wear. When the load is higher, the mainly wear mechanism are abrasive wear and delaminating wear of the combination.更多还原