THE FABRICATION OF COMPLEX TiAl-BASED TURBINE BLADES BASED ON STEREOLITHOGRAPHY

Abstract

Intermetallics TiAl and ceramic SiC are two important high-temperature structural materials, but it is difficult to fabricate turbine blades from them by traditional methods. In order to solve the problem, stereolithography and gel casting technologies were adopted. Impregnation and pyrolysis behaviors of polycarbosilane were examined for SiC preparation, and the microstructure evolution and mechanical properties of TiAl–SiC samples were mainly analyzed. The results showed that it was difficult to fabricate high-solid loading slurry of TiAl in gel casting, and porous TiAl preforms were fabricated. The TiAl intermetallic was easy to sinter by adding a small amount of nickel, and connected pores inside the samples formed after debinding. After the samples impregnated with polycarbosilane were pyrolyzed, their final microstructures included TiAl, SiC, Ti₃SiC₂, AlNi, and TiNi, and their high-temperature bending strength was between about 38 and 45 MPa at 1100 °C. Therefore, this method was feasible for the fabrication of complex TiAl–SiC turbine blades.