Near-net-shape fabrication of Ti₃AlC₂-based composites

A porous ceramic preform was fabricated by printing a powder blend of TiC, TiO₂, and dextrin. The presintered preforms contained a bimodal pore size distribution with intra-agglomerate pores (d₅₀ ≈0.7 μm) and inter-agglomerate pores (d₅₀ ≈ 30 μm), which were subsequently infiltrated by aluminum melt spontaneously in argon above 1050°C. A redox reaction at 1400°C resulted in the formation of dense Ti-Al-O-C composites mainly composed of Ti₃AlC₂, TiAl₃, Al, and Al₂O₃, which attained a bending strength of 320 MPa, a Young's modulus of 184 GPa, and a Vicker's hardness of 2.5 GPa.