Cu-infiltrated (Nb,W)C solid solution carbides

Binderless NbC with 0-25 wt% WC powder mixtures were pressureless sintered in vacuum at 1330, 1390 or 1450 degrees C to generate open porosity (Nb,W)C skeletons. The formation of residual minor amounts of W2C and WC was discussed as a function of WC addition and compared with thermodynamic predictions. The structures with 15-25 wt% WC addition with 16-35% open porosity were used as a skeleton for Cu infiltration at 1390 degrees C in H2. The microstructure of the as-sintered homogeneous (Nb,W)C grains in the skeleton changed into a core-rim structured grains after Cu infiltration due to the partial dissolution of Nb into the liquid Cu phase. The fracture toughness, hardness, Young's modulus, electrical conductivity and flexural strength of the as-sintered porous and near fully dense Cu-infiltrated materials were assessed and discussed.

Automated summary

Binderless NbC with 0-25 wt% WC powder mixtures were pressureless sintered in vacuum at different temperatures to generate open porosity (Nb,W)C skeletons. The formation of residual minor amounts of W2C and WC was discussed and compared with thermodynamic predictions. The microstructure of the as-sintered homogeneous (Nb,W)C grains in the skeleton changed after Cu infiltration due to the partial dissolution of Nb. The properties of the as-sintered porous and Cu-infiltrated materials were evaluated and discussed.