Microstructure and properties stability of Al-alloyed MoSi2 matrix composites
Artikel i vetenskaplig tidskrift, 2004

The development of structure and properties in the C40 Mo(Si,Al)2/Al2O3, Mo(Si,Al)2/SiC and Mo(Si,Al)2/ZrO2 composites prepared by SPS of MA powders, caused by the 5-h annealing at 1600 °C, was investigated. The structure coarsening and transformation of a retained phase were revealed in the annealed composites. Intergranular fracture, observed in the as-sintered composites, was completely transformed to transgranular cleavage failure after the annealing. A decrease in hardness and changes in fracture toughness were discussed in relation to the structure coarsening and transformation of the fracture mode. Surface oxidation of the Mo(Si,Al)2/Al2O3 and Mo(Si,Al)2/ZrO2 during the annealing led to the formation of Mo5Si3 near-surface layer containing inclusions of an aluminium silicate phase. Internal oxidation of SiC in the Mo(Si,Al)2/SiC composites prevented the oxidation of the Mo(Si,Al)2 phase in the near-surface region.

Microstructure

Fracture toughness

Thermal stability

Composite

Molybdenum silicides

Författare

Pavel Krakhmalev

Chalmers, Institutionen för materialteknik

Erik Ström

Chalmers, Institutionen för materialteknik

Changhai Li

Chalmers, Institutionen för materialteknik

Intermetallics

Vol. 12 225-233

Ämneskategorier

Materialteknik