Preparation and Properties of Ag-Based Electrical Contact Material Reinforced by Ti3AlC2 Ceramic and its Derivative Ti3C2Tx

As a new kind of two-dimensional carbide material, Ti3C2Tx has revealed its exceptional potentials in many applications. Herein, we successfully prepared the Ag/Ti3C2Tx composite by powder metallurgy and investigated its comprehensive properties by compared with Ag/Ti3AlC2 composite. The Ag/Ti3C2Tx was found to possess the 29% lower resistivity(30×10-3 μΩ·m) than Ag/Ti3AlC2(42×10-3 μΩ·m) and excellent machinability with intermediate hardness (64 HV), showing broad application prospect as non-toxic electrical contact materials. The improved conductivity of Ag/Ti3C2Tx composite is attributed to the metallicity of Ti3C2Tx itself, the good interface bonding between the Ti3C2Tx and Ag, and the microstructural features rendered by the deformability of Ti3C2Tx. Although the arc erosion resistance of Ag/Ti3C2Tx needs to be further improved, it is a powerful and potential alternative material for the Ag/CdO in the further.

Research Progress in Silver Zinc Oxide Electrical Contact Material

Since the performance of silver metal oxide (Ag/MeO) electrical contact materials directly affects the reliability and service life of switching apparatus, the related research on high-performance Ag/MeO electrical contact materials has not stopped. And with the rapid development of switching apparatus, higher and higher requirements are put forward for the performance of Ag/MeO electrical contact materials. Thanks to low and stable contact resistance, short arc burning time, good resistance to high current impulse (3000-5000 A) and good anti-arc erosion, silver zinc oxide (Ag/ZnO) more than just serves as an indispensable environmentally friendly alternative to silver cadmium oxide (Ag/CdO) electrical contact material, and has become one of the important research hotspots of Ag/MeO in recent years. Nevertheless, Ag/ZnO is suffering the increasingly serious challenges, especially the poor processability and electrical properties due to the easy segregation of zinc oxide (ZnO) during the process of preparation, which urge scholars at home and abroad to seek favorable methods to optimize the Ag/ZnO. As yet, impressive strides have been made in optimization the preparation process, nano-technology and additive modification of materials, and research on the failure mechanism of materials. Aiming to provide reference for optimizing Ag/ZnO electrical contact material, this review retrospects the research progress in Ag/ZnO electrical contact materials in recent years, and expounds the preparation methods, processing technology, modification research and failure mechanism of Ag/ZnO, and points out the future development directions of Ag/ZnO.

Fabrication of SiC@Cu/Cu Composites with the Addition of SiC@Cu Powder by Magnetron Sputtering

In view of the surface engineering application of electrical contact materials, SiC ceramic particles were introduced into copper matrix composites by the hot-press sintering method for the sake of enhancing the service life of copper matrix electrical contact materials. Magnetron sputtering technology was exploited to form the continuous copper film on the β-SiC powders in order to improve interface wettability between SiC powder and copper matrix. The SiC@Cu powders were treated by magnetron sputtering technology. Then, dynamic deposit behavior was described according to SEM results. The phase constitution, fracture morphology, relative density, porosity, Vickers hardness, and coefficient of thermal expansion of SiC@Cu/Cu composites with different SiC@Cu addition were analyzed in detail. The results showed that SiC@Cu powders with higher fraction in the SiC@Cu/Cu composites would decrease relative density and increase porosity, so it resulted in improvement of Vickers hardness. The addition of SiC@Cu decreased CTE values of the SiC@Cu/Cu composite, especially at high-level fraction SiC@Cu powder.