摘要 |
A powder-based material system having an intrinsic and stable degree of porosity provided by hollow ceramic spheres (26) in a fully dense matrix (27). A substrate (22) is formed from a metal powder (70), and may be partially sintered (60). A layer (24) of ceramic powder is arranged on the substrate including the pre-sintered hollow ceramic spheres plus a proportion of nano-sized ceramic particles effective to reduce the layer sintering temperature and to increase the sintering shrinkage of the layer to approximate that of the metal substrate during subsequent co-sintering. The substrate and layer are then co-sintered (61), such as with spark plasma sintering (32, 34, 36), at a temperature and for a duration to fully densify the ceramic powder matrix around the hollow spheres, thereby producing a metal/ceramic material system with low interface stress and with stable porosity during operational temperatures in a gas turbine engine.
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