Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation ...Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density （2.96 g/cm^3）, high gas tightness （1.0 mPa·cm^3）/s）, excellent thermal management function as a result of high thermal conductivity （194 W/（m·K） and low coefficient of thermal expansion （7.0×10^-6 K-1）. Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding （48 mPa·cm^3）/s） can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.展开更多
Three kinds of high volume fraction Sip/1199, Sip/4032 and Sip/4019 composites were fabricated by squeeze casting method. The results show that the clean Si /Al interfaces without interfacial reaction products can dec...Three kinds of high volume fraction Sip/1199, Sip/4032 and Sip/4019 composites were fabricated by squeeze casting method. The results show that the clean Si /Al interfaces without interfacial reaction products can decrease the interfacial thermal resistance. The composites have a low coefficient of thermal expansion (7.5×10-6℃-1) and high thermal conductivity ranging from 126 to 157.9 W/(m·℃). With increasing temperature, the specific capacity and the average coefficient of thermal expansion increases monotonically, the thermal diffusivity and the thermal conductivity decrease gradually. The specific capacity, average coefficient of thermal expansion, thermal diffusivity and the thermal conductivity of the composites decrease gradually with increasing Si content. The thermal conductivities of composites were calculated by theoretical models. Both Maxwell model and P.G model consider the reinforcement as nearly-round particles, and the interface thermal resistance of Sip/Al composite calculated by EMA method展开更多
文摘Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density （2.96 g/cm^3）, high gas tightness （1.0 mPa·cm^3）/s）, excellent thermal management function as a result of high thermal conductivity （194 W/（m·K） and low coefficient of thermal expansion （7.0×10^-6 K-1）. Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding （48 mPa·cm^3）/s） can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.
基金Project(2003AA305110) supported by the Hi-tech Research and Development Program of China
文摘Three kinds of high volume fraction Sip/1199, Sip/4032 and Sip/4019 composites were fabricated by squeeze casting method. The results show that the clean Si /Al interfaces without interfacial reaction products can decrease the interfacial thermal resistance. The composites have a low coefficient of thermal expansion (7.5×10-6℃-1) and high thermal conductivity ranging from 126 to 157.9 W/(m·℃). With increasing temperature, the specific capacity and the average coefficient of thermal expansion increases monotonically, the thermal diffusivity and the thermal conductivity decrease gradually. The specific capacity, average coefficient of thermal expansion, thermal diffusivity and the thermal conductivity of the composites decrease gradually with increasing Si content. The thermal conductivities of composites were calculated by theoretical models. Both Maxwell model and P.G model consider the reinforcement as nearly-round particles, and the interface thermal resistance of Sip/Al composite calculated by EMA method
