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To fabricate metal–ceramic multilayer hollow functionally gradient materials (FGMs) that might meet the requirement of repeated service and long working time of high temperature burners, such as spacecraft engine, the microstructure and properties of composites of stainless steel and partially stabilized zirconia were investigated. Samples of different proportions of stainless steel (316L) to partially yttria-stabilized zirconia (PSZ) were fabricated by powder extrusion and sintering method. Shrinkage, relative density, microstructure, micro-Vickers hardness, compression strength, bending strength, fractographic morphology, Young’s modulus, coefficient of thermal expansion, thermal diffusivity and thermal conductivity and electric-resistivity of gas-pressure sintered samples with different proportions of stainless steel were measured. The results shows that threshold of ceramic matrix composites (CMCs) and metal matrix composites (MMCs) are approximately equal to 50 vol.% 316L and 60 vol.% 316L, respectively, and there is some difference between mechanical properties and physical properties in transient point.

Multilayer metal-ceramic gradient composite pipes were extruded through simultaneous extrusion of different types of particulate pastes composed of different proportions of stainless steel (316L) to partially yttria-stabilized zirconia (PSZ) with binder by means of multi-billet extrusion, then were solidified utilizing gas-pressure sintering. The multilayer composite pipes have sound transitional boundaries between adjacent layers. Because of the composition gradient, transitional boundaries between adjacent layers possess good bonding, and no interfacial decohesion occurs during flexural and compressive loading, which shows relatively high bonding strength between adjacent layers. In summary, multilayer metal-ceramic gradient composite pipe with good interfacial bonding between adjacent layers can be fabricated utilizing multi-billet extrusion and sintering.