Adapting the co-sintering behaviour of metal-ceramic composites

The combination of metal and ceramic layers can be useful in many different application fields as solid oxide fuel cells, filter elements, in medical engineering or for wear-resistant components.The most promising, cost-effective and especially the way with the highest degree of freedom in regard to the design is using a combined shaping (co-shaping) and sintering (co-sintering). However, differences in densification behavior during co-sintering can lead to stresses and defects as cracks, delaminations or cambering of the composite.The presentation will show the adaption of the co-sintering behavior of ceramic and metallic materials using a high energy milling (HEM) step to influence the sintering behavior of the metallic powders. The change of the sintering behavior can be related with a change in particle size, specific surface area and crystallite size.Co-sintering results of composites produced by different shaping technologies consisting of yttria stabilized zirconia and an iron chromium alloy using the starting powder in comparison to the powder modified by HEM are shown.The high energy milling of the metallic powders allows for the first time a good adaption of the sintering behavior of the ceramic and metallic materials. Using this powder enables a defect free co-sintering of the composites, independent from the used shaping technology (for example tape casting or additive manufacturing)