Effect of Ni–P alloy coating on microstructures and properties of vacuum brazed joints of SiCp/Al composites

Abstract

Compared without electroless Ni–P alloy coating on the SiCp/Al composites, the paper describes the effect of Ni–P deposited layer on the microstructure evolution, shear strength, airtightness and fracture behavior of vacuum brazed joints. Void free and compact reaction layers along the 6063Al/Ni–P deposited layer/filler metal interfaces indicated that the joints exhibit high airtightness with He-leakage less than [Formula: see text] [Formula: see text]. Energy Dispersive X-ray Spectroscopy (EDS) analysis showed that the reaction layers mainly included brittle Al–Ni and Al–Cu–Ni intermetallics, where fracture occurred in priority and the shear strength was less than 90 MPa. However, without Ni–P alloy coating, sound joints with high shear strength of 100.1 MPa but low airtightness with He-leakage higher than [Formula: see text] were also obtained at 590[Formula: see text]C for soaking time of 30 min. In this case, a few holes that occurred along the filler metal/SiC particle interface significantly decreased the compactness of the joints. Therefore, according to the requirements in practical applications, suitable choice was provided in this research.

Advancements in SiC-Reinforced Metal Matrix Composites for High-Performance Electronic Packaging: A Review of Thermo-Mechanical Properties and Future Trends

“…At present, metals such as Ni-P [ 90 ], MgO [ 54 ], Cu [ 91 ], Cr [ 92 ] and Ti [ 93 , 94 ] are all deposited on the surface of SiCp as coatings to prevent contact between SiCp and molten Al and inhibit the occurrence of adverse interface reactions. Li et al [ 95 ] the electroless plating method is adopted to Cu plating on the surface of SiCp, by means of pressureless infiltration technique was used to prepare the SiCp/Al composite materials, has not found the existence of Al 4 C 3 , explains the Cu coating can effectively inhibit really interface reaction, but it does not represent no interface reaction.…”