Advanced materials / High-temperature materials /

Slicide matrix composites

Functionally graded Mo/Mo silicide composite

General description

New class of composites formed by continuous molybdenum framework embedded in a silicide matrix exhibiting outstanding high temperature oxidation resistance and mechanical properties. They are prepared by c (PARS) based on infiltration of porous skeletons of molybdenum with molten silicon.

Main benefits

Mo/Mo silicide composites combine high temperature oxidation resistance provided by silicide matrix (forming silica) and high temperature strength, ductility and creep resistance enhancement yielded by Mo reinforcements. They overcome ceramic materials suffering from high temperature brittleness as well as refractory metals suffering from poor high temperature oxidation resistance.

 Mo_Mo silicide structure Structure of Mo/Mo silicide composite formed by Mo wires embedded in silicide matrix prepared by pressure assisted reactive synthesis

Main properties

The experimental tests confirmed the outstanding oxidation resistance of Mo/Mo silicide composites. It is confirmed by TG measurements where Mo and Mo/Mo silicide composites are compared.
Mass change on temperature aMass change dependence on temperature during heating of Mo preform and Mo/Mo silicide composite sample in air
Mass change on temperature b Mo/Mo silicide composite record in larger resolution

The newly developed gradient Mo/MoxSiy composite has high temperature bending strength of 289 MPa at 1150 °C what clearly exceeds that of currently used top PM 1000 material with the strength of 160 MPa (project SILTRANS 7th FP EU).

Main applications

Unique combination of properties predetermine the application of Mo/Mo silicide composites in most heavily loaded constructions exposed at high temperatures in aggressive environments. Typical examples include:

Additional reading

SENČEKOVÁ, L. - IŽDINSKÝ, K. - SIMANČÍK, F. - MINÁR, P. - NOSKO, M. - ŠVEC, P. The effect of Nb interlayers on compaction of Mo/Mo silicide composites. In Kovové materiály, 2012, roč. 50, s.425-432. (0.451 - IF2011). (2012 - Current Contents, Scopus, WOS). ISSN 0023-432X.

SENČEKOVÁ, L. - IŽDINSKÝ, K. - SIMANČÍK, F. - ŠTEFÁNIK, P. - ŠVEC, P. The Effect of Ni Interlayers on Compactions of Mo/Mo Silicide Composites. In Materials Science Forum, 2014, vol.782, pp. 507-512. ISSN 0255-5476.

IŽDINSKÝ, K. - SENČEKOVÁ, L. - SIMANČÍK, F. - BERONSKÁ, N. - ŠVEC, P. Mo/Mo silicide composites prepared by pressure-assisted reactive infiltration. In Kovové materiály, 2015, vol.53, pp.391-397. (Current Contents, Scopus, WOS ). ISSN 0023-432X.