Improving effect of carbonized quantum dots(CQDs)in pure copper matrix composites

碳量子点(CQD)在纯铜基复合材料中的增强作用

Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was prepared by powder metallurgy method.The composite powder was prepared by molecular blending method and ball milling method at first,and then densified into bulk material by spark plasma sintering(SPS).X-ray diffraction,Raman spectroscopy,infrared spectroscopy,and nuclear magnetic resonance were employed to characterize the CQD synthesized under different temperature conditions,and then CQDs with a higher degree of sp^(2)were utilized as the reinforcement to prepare composite materials with different contents.Mechanical properties and electrical conductivity results show that the tensile strength of the 0.2 CQD/Cu composite material is~31%higher than that of the pure copper sample,and the conductivity of 0.4 CQD/Cu is~96%IACS,which is as high as pure copper.TEM and HRTEM results show that good interface bonding of CQD and copper grain is the key to maintaining high mechanical and electrical conductivity.This research provides an important foundation and direction for new carbon materials reinforced metal matrix composites.

碳量子点(CQD)的核心结构为sp^(2)碳,可以像石墨烯和碳纳米管一样作为金属基体中的增强相。本文采用粉末冶金法制备了CQD/Cu复合材料,先用分子共混法和球磨法制备复合粉末,再用放电等离子烧结(SPS)致密化成块状材料。利用X射线衍射、拉曼光谱、红外光谱和核磁共振对不同温度条件下合成的CQD进行表征,然后利用sp2含量较高的CQD作为增强剂制备不同含量的复合材料。力学性能和电导率结果表明:0.2 CQD/Cu复合材料的抗拉强度比纯铜试样高~31%,0.4 CQD/Cu复合材料的电导率为~96%IACS,与纯铜相当。TEM和HRTEM结果表明,CQD与铜晶粒良好的界面结合是保持高力学性能和电导率的关键。本研究为新型碳材料增强金属基复合材料的研制提供了重要的基础和方向。