Micro/nano-mechanical properties evolution and degradation mechanism of Ti3AlC2 ceramic reinforced Ag-based composites under high-temperature arc corrosion

Abstract

Ti3AlC2 ceramic-reinforced Ag matrix composites exhibit superior electrical contact performance. However, the arc corrosion mechanism of the Ti3AlC2 reinforcing phase has not been clarified; in particular, the intrinsic relationship between the microstructure and mechanical properties needs to be further explored. In this work, by combining micro/nano-indentation, microstructural and chemical composition analysis, COMSOL simulation, and accelerated aging experiments, the relationship among phase transition, microstructural evolution, and macro/micro/nano-mechanical property changes were compared and analyzed. The cycles of arc discharge produced heat accumulation, which was transmitted from the contact surface to the interior in a gradient (divided into Areas α, β, γ). Changes in the structural dissociation, oxidation, and interfacial bonding of Ti3AlC2 with the Ag matrix resulted in different micro/nano-mechanical properties in these areas in terms of micro-hardness, nano-hardness, modulus, and elastic-plasticity. These findings demonstrate the key role of the phase and microstructural evolution of Ti3AlC2 on the mechanical properties of such composites while also providing a mechanical theoretical basis for future structural design and interfacial optimization of eco-friendly Ti3AlC2-reinforcing phases in Ag matrix composites.