| With the rapid development of electronic devices and systems towards large-scale integration,miniaturization,lightweight and high power,the heat dissipation of devices has increasingly become the bottleneck of further development of such devices.6063Al has good thermoplasticity,low density,high strength,good thermal conductivity,low cost,simple processing and other characteristics,and is widely used in aerospace,transportation,electronics,communications and other fields.However,in the face of the large amount of heat generated by high-end equipment,the current use of 6063Al heat dissipation capacity is far from meeting the requirements of heat dissipation.Finding a 6063Al matrix composite with higher heat dissipation capability and its preparation method is one of the ways to solve the heat dissipation problem of high power and high integration devices.This will not only help to expand the application of 6063Al and promote the development of microelectronic devices,but also have important theoretical significance for the theoretical study of material interface heat dissipation.In this paper,graphene composite coatings modified by silane coupling agent were prepared on 6063Al substrate by pulsed electrophoresis deposition.The structure and morphology of thermal conductive materials were determined by TGA,AFM,Raman,FTIR,XPS and SEM.The thermal conductivity of thermal conductive materials was measured by laser thermal conductivity meter.The thermal conductivity of thermal conductive materials was measured by infrared thermal imager.The hydrophobicity of thermal conductive materials was characterized by contact angle.The corrosion resistance of thermal conductive materials was measured by electrochemical test.The results are as follows:（1）Preparation and structure test of graphene/6063Al modified by silane coupling agent by electrophoretic depositionGraphene/6063Al composites modified by silane coupling agent were prepared by self-assembly,hydrazine hydrate reduction and electrophoretic deposition（EPD）.The thicknesses of KH540-GO/Al and KH540-r GO/Al composites were 3.4 and 1.7μm,respectively.The thickness of KH550-GO/Al and KH550-r GO/Al are 3.4 and 1.8μm,respectively.The thickness of KH560-GO/Al and KH560-r GO/Al are 4.2 and 1.6μm,respectively.The disorder degree of graphene oxide composites modified by silane coupling agent is higher than that of graphene oxide GO,while the disorder degree of graphene oxide composites modified by silane coupling agent is higher than that of graphene oxide composites reduced by silane coupling agent.There is an Al-O-Si-O-C covalent bond between Al and GO（r GO）.（2）Thermal conductivity of graphene/6063Al composites modified by silane coupling agentThe thermal conductivity of the composite thermal conductive material was tested by infrared thermal imager and laser thermal conductivity instrument.After 0 s,40 s,70 s,100 s and 130s,the surface temperatures of KH540-r GO/Al reached 19.5℃,78.3℃,132.8℃,173.3℃and 221.9℃,respectively.The surface temperatures of KH550-r GO/Al were 19.4℃,77.1℃,133.6℃,172.9℃and 218.4℃,respectively.The surface temperatures of KH560-r GO/Al were 19.6℃,79.5℃,132.8℃,172.3℃and 217.2℃,respectively.The thermal conductivity of Al matrix is 194.2 W/m·K,191.2 W/m·K,186.9 W/m·K and 170.3 W/m·K,respectively,at 50℃,100℃,150℃and 200℃.The thermal conductivity of KH540-r GO/Al is 206.1 W/m·K,205.3 W/m·K,199.3 W/m·K and 197.3 W/m·K,respectively.The thermal conductivity of KH550-r GO/Al is212.6 W/m·K,201.2 W/m·K,201.0 W/m·K and 202.4 W/m·K,respectively.The thermal conductivity of KH560-r GO/Al is 221.1 W/m·K,201.7 W/m·K,198.3 W/m·K and 194.6 W/m·K,respectively.Due to the modification of silane coupling agent,covalent bonds were established between Al and r GO,which promoted the phonon transfer between Al and r GO,and ultimately improved the thermal conductivity of the material.（3）Corrosion resistance of graphene/6063Al thermal conductive composites modified by silane coupling agentThe contact angle of Al matrix is 97.86°.The contact angles of KH540-GO/Al and KH540-r GO/Al were 140.21 and 149.61°,respectively.The contact angles of KH550-GO/Al and KH550-r GO/Al were 140.83 and 149.13°,respectively.The contact angles of KH560-GO/Al and KH560-r GO/Al were 140.21 and 149.61°,respectively.The corrosion potential and corrosion current density of Al are-0.798 V and 1.361×10-4A/cm2,respectively.The corrosion potentials of KH540-GO/Al and KH540-r GO/Al were-0.700V and-0.566 V,respectively,and the corrosion current densities were 1.155×10-4 A/cm2 and9.307×10-5 A/cm2,respectively.The corrosion potentials of KH550-GO/Al and KH550-r GO/Al were-0.633 V and-0.689 V,respectively,and the corrosion current densities were 1.267×10-4A/cm2and 8.406×10-5 A/cm2,respectively.The corrosion potentials of KH560-GO/Al and KH560-r GO/Al were-0.751 Vand-0.785 V,respectively,and the corrosion current densities were1.020×10-4 A/cm2 and 9.793×10-5 A/cm2,respectively.The order of corrosion current density of KH540-r GO/Al,KH550-r GO/Al and KH560-r GO/Al is KH550-r GO/Al<KH540-r GO/Al<KH560-r GO/Al<KH560-r GO/Al.In 3.5%Na Cl solution,after 500 s,the OCV of Al is-0.751 V.The OCVs of KH540-GO/Al and KH540-r GO/Al were-0.740 V and-0.741 V,respectively.The OCVs of KH550-r GO/Al and KH550-GO/Al were-0.741 V and-0.747 V,respectively.The OCVs of KH560-r GO/Al and KH560-GO/Al were-0.740 V and-0.745 V,respectively. |
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