Preparation of Ti3AlC2–Al Cermets by Combined Use of SHS of Ti3AlC2 Porous Skeleton and Spontaneous Infiltration with Al and Al-Based Melts

Abstract

Ti₃AlC₂–Al cermets were produced by a new method combining SHS and spontaneous infiltration. SHS was applied to obtain a ceramic Ti₃AlC₂ MAX phase with a porous structure, which in the hot state was brought into contact with Al melt and Al-based melts for spontaneous high-temperature infiltration. The optimum time delay between the end of combustion and the start of infiltration with melt was found to be 7–8 s. This time pause was shown to be enough to complete the structure formation of MAX phase in the porous skeleton and to spontaneously infiltrate the pores with melt. Upon infiltration with pure Al melt, Ti₃AlC₂ MAX-phase was shown to completely decompose to TiC and TiAl₃. The presence of 12% Si or 32% Cu in Al melt contributed to the partial retention of Ti₃AlC₂ in SHS cermet. It was found that the yield stress of cermets obtained by infiltration of SHS skeleton with Al–12% Si melt is 410 MPa that exceeds that for pure Al–12% Si alloy (~260 MPa) by approximately 58%.