离焦量对SLM成形GNPs/AlSi10Mg复合材料性能的影响

Effect of defocus amount on properties of GNPs/AlSi10Mg composites formed by SLM

采用选区激光熔化成形技术制备GNPs/AlSi10Mg复合材料,研究成形过程中离焦量对复合材料组织形貌、硬度、摩擦磨损性能的影响规律。结果表明:随着离焦量从负离焦到正离焦,复合材料成形质量、微观组织及性能呈非对称变化,微观形貌为不同尺寸的胞状晶粒,离焦量为-4 mm时,存在较多孔隙。当离焦量为2 mm时,复合材料成形质量较好,内部气孔较少,石墨烯分布较为均匀,与基体存在良好的界面结合,未出现明显的团聚效应;复合材料硬度较大为178HV 0.2,耐磨性较高,摩擦系数为0.1245,磨损损失量为1.95 mg。

In this paper,GNPs/AlSi10Mg composites are prepared by selective laser melting technology.The effects of defocus amount on the microstructure,hardness,friction and wear properties of the composites during formation are studied.The results show that the forming quality,microstructure and properties of the composites change asymmetrically from negative defocus to positive defocus.The microstructure consists of cellular grains of different sizes.There are many pores when the defocus is-4 mm.When the defocus amount is 2 mm,the composites have good forming quality with less internal pores.The distribution of graphene is relatively uniform.Without obvious agglomeration effect,there is a good interface bonding with the substrate.The hardness of the composites is as high as 178 HV 0.2.The wear resistance is high,the friction coefficient is 0.1245,and the wear loss is 1.95 mg.