空间结构增强铜基复合材料的摩擦磨损特征

为实现铜基复合材料性能的有效调控，采用激光选区熔化成形制备了单元尺寸分别为5.00、3.75、2.75、1.75和0.75 mm的18Ni300空间结构增强体，然后在挤压铸造条件获得了具有不同增强体分布的18Ni300空间结构增强铜基复合材料. 研究了复合材料的微观组织、硬度、摩擦磨损性能和磨损表面形貌. 结果表明:随着空间结构单元尺寸的减小，复合材料增强体体积分数不断增加，硬度和耐磨性提高. 结构单元尺寸为0.75 mm时，复合材料增强体体积分数为13.35%，硬度达到HBW120，为铜基体硬度的1.71倍；载荷40 N、线速度0.75 m/s、磨损时间25 min 条件下的体积磨损量为35.4 mm3，比铜基体磨损量降低58%. 由于增强体的作用，复合材料的磨损机制由纯铜的黏着磨损转变为磨粒磨损. 

Tribological Properties of Copper Matrix Composite with Lattice Reinforcement

In order to effectively tune microstructure and properties of copper matrix composites, 18Ni300 lattices with different cell sizes of 5.00 mm, 3.75 mm, 2.75 mm, 1.75 mm, 0.75 mm were formed by selective laser melting. After being solidified with copper melt under pressure of squeeze casting process, the lattices combined with copper matrix and formed composites. The microstructure, hardness and wear morphology of samples were observed and analyzed, and wear tests of the composites were investigated by pin-on-disk procedure. The results indicate that the lattices performed a key role to improve the properties of the composites. The composite with lattice of 0.75 mm cell size showed the highest hardness and best wear resistance. The hardness reached HBW120 and was 1.71 times of the Cu matrix. The wear volume was 35.4 mm3 and was 58% lower than that of the Cu matrix. The wear mechanism of the composite was abrasive wear.