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
The properties of the joints are dictated by the nature, distribution, and morphology of the phases formed at the interface. The mechanical properties of brazed joints are well documented in the literature, contrarily...The properties of the joints are dictated by the nature, distribution, and morphology of the phases formed at the interface. The mechanical properties of brazed joints are well documented in the literature, contrarily to their electrochemical behaviour. Thus, the main objective of this study was to understand the influence of the phases formed at the interface on the corrosion behaviour of commercially pure Ti brazed joints, produced by using TiCuNi, eutectic Ag Cu, and Ag filler foils. The electrochemical behaviour of the Ti joints was accessed by open circuit potential and potentiodynamic polarization tests in phosphate buffer saline solution electrolyte at body temperature. Results showed that Ag-based fillers induced susceptibility to micro-galvanic corrosion between the Ag-rich and Ti phases formed at the interface and commercially pure Ti base metal. However, no significant differences were observed between the joint system and the base material when brazing with TiCuNi filler.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supported by Portuguese FCT,under the reference project UIDB/04436/2020 and M-ERA-NET/0001/2015 project。
文摘The properties of the joints are dictated by the nature, distribution, and morphology of the phases formed at the interface. The mechanical properties of brazed joints are well documented in the literature, contrarily to their electrochemical behaviour. Thus, the main objective of this study was to understand the influence of the phases formed at the interface on the corrosion behaviour of commercially pure Ti brazed joints, produced by using TiCuNi, eutectic Ag Cu, and Ag filler foils. The electrochemical behaviour of the Ti joints was accessed by open circuit potential and potentiodynamic polarization tests in phosphate buffer saline solution electrolyte at body temperature. Results showed that Ag-based fillers induced susceptibility to micro-galvanic corrosion between the Ag-rich and Ti phases formed at the interface and commercially pure Ti base metal. However, no significant differences were observed between the joint system and the base material when brazing with TiCuNi filler.
