Oxidation of Ti3SiC2 between 900 and 1200 °C in Air

Abstract

Ti 3 SiC 2 materials were synthesized by hot pressing using a new startingmaterial system consisting of a TiC x (x=0.6)/Si powder mixture. The oxidation of Ti 3 SiC 2 at temperatures between 900 and 1200°C in air for up to 100 h resulted in the formation of an outer TiO 2 layer, an intermediate SiO 2 -rich layer and an inner (TiO 2 + SiO 2 ) mixed layer. During oxidation, Ti diffused outwards to form the outer TiO 2 layer, and oxygen transported inwards to form the inner (TiO 2 + SiO 2 ) mixed layer. At the same time, the carbon in Ti 3 SiC 2 escaped into the air. Below the scale, there was a narrow oxygen-affected zone, The oxidation at the scale-matrix interface proceeded by the disintegration of the lamellar Ti 3 SiC 2 grains to form crystallites with a size of a few tens of nanometers containing oxygen. The detailed scale characteristics and oxidation mechanism are described.

Cyclic-Oxidation Behavior of Ti3Al0.7Si0.3C2 Compounds Between 900 and 1100 °C in Air

“…1b indicates that the lamellar grains have a laminated microstructure. Such a microstructure was also found in Ti 3 SiC 2 , Ti 3 AlC 2 , and Cr 2 AlC [8,13,17]. Figure 2 shows the XRD patterns of Ti 3 AlC 2 , Ti 3 Al 0.7 Si 0.3 C 2 and Ti 3 SiC 2 .…”

“…For the purpose of comparison, Ti 3 SiC 2 [8], Ti 3 AlC 2 [13], and Cr 2 AlC [17] were also prepared in a similar manner.…”

“…SiO 2 ) mixed layer. During oxidation, the inward diffusion of oxygen and the outward diffusion of Ti and CO or CO 2 predominated [8]. Ti 3 AlC 2 similarly oxidized to TiO 2 and Al 2 O 3 , together with the evolution of CO or CO 2 [9][10][11][12][13].…”

“…The isothermal oxidation behavior of Ti 3 SiC 2 [2][3][4][5][6][7][8] and Ti 3 AlC 2 [9][10][11][12][13] has been extensively studied. The isothermal oxidation of Ti 3 SiC 2 at temperatures between 900 and 1200°C in air resulted in the formation of an outer TiO 2 layer, an intermediate SiO 2 -rich layer and an inner (TiO 2 ?…”

Oxygen diffusivity in alumina scales grown on Al-MAX phases

“…While over 60 compounds have been reported, a much smaller subset claims optimum oxidation resistance at temperatures greater than 1000°C. These include Ti 3 AlC 2 , Ti 2 AlC, and Cr 2 AlC, which are the primary compounds reported to develop protective alumina scales [2][3][4]. These properties and attractive thermal expansion matches with alumina, YSZ, (yttria stabilized zirconia) or Ni alloys make alumina-forming MAX phase compounds an interesting option for hybrid high temperature systems with possible implications for turbine components [5].…”