Effects Of Si Ion Implantation On Wettability And Interfacial Behavior Of Metal/SiC Systems

Silicon carbide?SiC?,as a kind of promising structure-function integrated material,has been extensively used in high temperature structural ceramic components,semiconductor devices and metal matrix composites,which are often involved in the wettability and interface behavior of molten metals on the surface of SiC ceramics.Generally,the poor wettability was obtained in metal/highly covalent ceramic systems,which can be improved by adding active metal elements to the metal and surface modification of the ceramic?such as plating and sintering metallization?.In this paper,Si was implanted into 6H-SiC surface with the doses of 5×10¹⁵,1×10¹⁶ and 5×10¹⁶ ions/cm².After the surfaces of Si-implanted 6H-SiC substrates were characterized,the wettability and interface behavior of?Cu,Al,Sn?/6H-SiC and Cu-Al/6H-SiC systems were investigated.The Si ion mainly exists in the forms of element and oxide on the surface of 6H-SiC.With the implantation dose rising from 5×10¹⁵ to 5×10¹⁶ions/cm²,much more Si and C vacancies and free Si or C atoms can be generated on the surface of 6H-SiC,and the crystallinity gradually decreased,resulting in increases in reactive sites and surface energy on the substrate.In Cu/SiC systems,the thichness of graphite layer at the interface gradually decreased with the increase of Si implantation dose,and the wettability was deteriorated.While implanting the same doses of Si ion,the thickness of graphite layer on Cu/Si-terminated 6H-SiC?Cu/Si-SiC?interface was less than that on Cu/C-terminated 6H-SiC?Cu/C-SiC?interface,but a wider graphite layer was generated in the triple line area.As a result,the wettability of Cu/C-SiC systems was better than that of Cu/Si-SiC systems.The graphitization of 6H-SiC substrate was strengthened with increasing the wetting temperature,resulting in the rupture of the SiC substrate.In Al/SiC systems,the thickness of interfacial reaction product?Al₄C₃?gradually decreased,while the width of the reaction product gradually increased at the triple line area,and the equilibrium contact angle increased with the increase of the Si implantation dose.Moreover,the thicknesses of reaction product layer of Al/C-SiC systems were smaller than those of Al/S-SiC systems,but the wettability of the Al/C-SiC systems was better than that of the Al/C-SiC systems,respectively.The reactive behaviour of Al/SiC interface was more severe with increasing wetting temperature,and the molten Al was volatilized at the higher temperature,so it is difficult for the Al/SiC systems to reach the equilibrium.The wettability transformed from non-wetting into wetting in Sn/C-SiC systems with the increase of Si implantation dose;however,the wettability had almost no change in Sn/Si-SiC systems.In Cu-?5,10,15,20,30,35,50?Al/Si-SiC systems,the graphitization degree at the interface gradually decreased with increasing the Al concentration.In particular,the graphitization phenomenon disappeared while the Al concentration was over 45%.In Al-?5,10,15,30?Cu/Si-SiC systems,the reaction product at the interface gradually decreased with increasing the Cu content,and the wettability was deteriorated.In Cu-?45,50,70?Al/Si-SiC systems,the Si ion implantation can improve significantly the wettability of the Cu-45Al/SiC system but weaken that of the Cu-?50,70?Al/SiC systems.Moreover,the equilibrium contact angle increased in Cu-?50,70?Al/SiC systems with the increase of Si implantation dose.