Current-carrying wear mechanism of alternating magnetic field–assisted cold-sprayed Cu-based composite coatings

This research integrated alternating magnetic fields (AMF) and cold spraying to build the firstAMF–assisted cold-spraying platform. This platform was used to fabricate Cu–15 %TiC coatings, with an aim to address serious current-carrying wear issues in electrical engineering. Variations in the forming qualities, mechanical properties, service performances and microstructures of two coatings prepared with and without an applied AMF (referred to as 0 and 1000 Gs coatings, with 1000 Gs being the field intensity) were comprehensively investigated. After being assisted by AMF, the porosity of the coating decreased from 0.885 % to 0.838 %, the roughness Ra decreased from 3.044 μm to 3.901 μm, the hardness increased from 115.6 HV to 125 HV, and the volume of current-carrying wear at 5 A decreased from 72,716,107 μm³ to 59,753,652 μm³ .With AMF application, the numbers of deformation twins and stacking faults increased within the coating microstructure and a minor texture orientation was observed. These microstructural evolutions resulted in synergistically enhanced mechanical properties and service performance of the 1000 Gs coating. Findings from characterisations and calculations suggested that Joule heating was the primary cause for the formation of deformation twins and stacking faults under the AMF; meanwhile, magneto-plasticity was possibly a secondary cause. Overall, this research demonstrates that the use of AMF exhibits notable potential for fabricating coatings with excellent service performance and mechanical properties via cold spraying and additive remanufacturing.