Preparation of Ti3AlC2 matrix composites by selective laser melting combined with pressureless sintering

Selective laser melting (SLM) has the ability to net complex-shaped structures. In this study, Ti3AlC2 matrix composites were fabricated by SLM and pressureless sintering of an Al-TiO2-TiC-CNT system. The results show that the formation process of the sample during SLM involved the in-situ reaction of Al with TiO2 to form TiAl3 and Al2O3. TiAl3 subsequently reacted with TiC to synthesise Ti3AlC2 during the pressureless sintering process. Results also show that variations of the laser power had a correlated effect on the element, and by increasing or decreasing the laser power three distinctive areas could be seen on the sample: the TiAl3/TiC composite area, the unreacted area and alumina area according to the phase composition. As the laser power increased, the TiAl3/TiC composite area increased, the unreacted area decreased and the chemical reaction between the material components became more sufficient. The laser power also had a significant influence on the surface topography of the SLM sample. When the laser power increased from 40 to 60 W, the surface morphology of the sample evolved from the initial disordered network to the mutually stacked structure perpendicular to the scanning direction and eventually became uniformly distributed.