Achieving highly conductive Ag/Ti3AlC2 composite by inhibiting interdiffusion

Interfacial behavior in composites significantly influences their properties. Ag-based composites reinforced with Ti₃AlC₂ (a MAX phase) are promising for electrical contacts. However, interdiffusion between the Ag matrix and Ti₃AlC₂ increases impurities in the Ag matrix, adversely affecting electrical resistance and raising operational temperatures. To address this, we developed a novel partial etching pretreatment that selectively etches Al atoms from the near-surface region of Ti₃AlC₂, creating a Ti₃C₂ surface layer. This innovative approach confines interdiffusion mainly within the Ti₃C₂ layer, preserving the Ag matrix's high electrical conductivity. Experimental results for Ag-based composites with 10 wt.% of Ti₃AlC₂, subjected to 0.5 h etching, show a significant 51 % reduction in electrical resistivity with only a 10 % decrease in mechanical properties compared to Ag/Ti₃AlC₂. These findings underscore the effectiveness of manipulating A-site elements in Ti₃AlC₂ to enhance the performance of Ag-based composites, offering valuable insights for advanced electrical material design.