Reaction, densification, and mechanical properties of Ti2AlCx ceramics at low applied pressure and temperature

Ti2AlCx ceramic was produced by reactive hot pressing (RHP) of Ti:Al:C powder mixtures with a molar ratio of 2:1:1-.5 at 10-20 MPa, 1200-1300 degrees C for 60 min. X-ray diffraction analysis confirmed the Ti2AlC with TiC, Ti3Al as minor phases in samples produced at 10-20 MPa, 1200 degrees C. The samples RHPed at 10 MPa, 1300 degrees C exhibited >= 95 vol.% Ti2AlC with TiC as a minor phase. The density of samples increased from 3.69 to 4.04 g/cm(3) at 10 MPa, 1200 degrees C, whereas an increase of pressure to 20 MPa resulted from 3.84 to 4.07 g/cm(3) (2:1:1 to 2:1:.5). The samples made at 10 MPa, 1300 degrees C exhibited a density from 3.95 to 4.07 g/cm(3). Reaction and densification were studied for 2Ti-Al-.67C composition at 10 MPa, 700-1300 degrees C for 5 min showed the formation of Ti-Al intermetallic and TiC phases up to 900 degrees C with Ti, Al, and carbon. The appearance of the Ti2AlC phase was >= 1000 degrees C; further, as the temperature increased, Ti2AlC peak intensity was raised, and other phase intensities were reduced. The sample made at 700 degrees C showed a density of 2.87 g/cm(3), whereas at 1300 degrees C it exhibited 3.98 g/cm(3); further, soaking for 60 min resulted in a density of 4.07 g/cm(3). Microhardness and flexural strength of Ti2AlC0.8 sample were 5.81 +/- .21 GPa and 445 +/- 35 MPa.

Automated summary

The study investigates the production of Ti2AlCx ceramics using different processing conditions and raw material ratios, analyzing their properties through methods such as density and phase analysis. The results indicate that high-quality Ti2AlCx ceramics can be produced under specific conditions.