Silicide-based composite material and process for producing the same

1. A silicide-based composite material comprising:

a silicide of Mo, B, W, Nb, Ta, Ti, Cr, Co, Y, or a combination thereof;

20-40 wt % of Si 3 N 4 ;

0.5<8 wt % of Y 2 O 3 ;

0.5-6 wt % of CeO 2 and

up to 4 wt % of impurities, the impurities comprising Al, C, Fe, Ca, O, N, or a combination thereof.

2. The material of claim 1 , wherein the silicide is selected from the group consisting of MoSi 2 , Mo 5 SiB 2 , Mo 3 Si, Mo 5 SiB 2 , α-Mo—Mo 5 SiB 2 —Mo 3 Si, WSi 2 , NbSi 2 , TaSi 2 , TiSi 2 , CrSi 2 , CoSi 2 , YSi 2 , Mo 5 Si 3 , Ti 5 Si 3 , and combinations thereof.

3. The material of claim 1 , further comprising

20-40 wt % of Si 3 N 4 ,

0.5-6 wt % of Y 2 O 3 ,

0.5-4 wt % of CeO 2 ,

<0.1 wt % of Al,

<0.5 wt % of C,

<0.1 wt % of Fe,

<0.1 wt % of Ca,

<1.5 wt % of O,

<0.5 wt % of N, and

the remainder being MoSi 2 .

4. The material of claim 1 , wherein the material has a porosity lower than 0.5%, a density of 4-5 g/cm3, a directionally solidified grain structure, and an average grain size of 50-150 μm.

5. A gas turbine hot gas path component, the component being a bucket, a nozzle, or a shroud made of the material of claim 1 .