Revealing the adhesion strength and electronic properties of Ti3SiC2/Cu interface in Ti3SiC2 reinforced Cu-based composite by a first-principles study

Abstract

Ti3SiC2 reinforced Cu-based composites (TRCCs) are regarded as a promising electrical contact material. The adhesion strength between Ti3SiC2 and Cu matrix is determined by the interfacial properties of TRCCs. In this work, the structural properties and bonding characteristics of Ti3SiC2(001)/Cu(111) interface in the TRCCs were investigated by the first-principles calculations. Twenty-four types of interface models were taken into account, and their work of adhesion (Wad), interfacial energy and electronic properties were discussed. The results indicate that the Ti2(C)-termed Ti3SiC2(001) is the most stable in the entire range of ΔμTi, while the Ti2(C)- and Ti1(C)-termed surfaces have the lowest surface energy in the poor and rich ΔμC, respectively. Among all the interfacial models, the Ti- and Si-termed interfaces with the same terminations have the comparable Wad, and the C(Ti1)-fcc-Cu interface has the maximum adhesion strength with the Wad of 6.27 J/m2, while the Ti2(C)-fcc-Cu interface has the lowest interfacial energy with the value of −4.48 ∼−1.03 J/m2. The analysis of electronic properties shows that the adhesion strength of Ti-, Si-and C-termed interfaces is primarily contributed by Ti-Cu metallic bonding, Si-Cu covalent bonding and CCu covalent bonding, respectively. Our studied results could help to understand the interfacial strengthening mechanism between Ti3SiC2 and Cu matrix.