Three dimensional printing enables realization of complex shape rare earth permanent magnet that enable unlocking the full potential of electrical devices for energy consumption and renewable energy production.

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All‐oxide continuous fiber‐reinforced ceramic matrix composites are enabling materials for high‐temperature structural applications in oxidizing environments. However, their industrial use requires further improvements in material performance as well as a significant reduction of the processing costs. This article gives some insight into a novel colloidal processing route. A porous mullite matrix was designed to obtain damage‐tolerant behavior as well as high‐temperature long‐term stability. Laminated composites were formed with conventional techniques similar to the manufacture of polymer matrix composites. This simple and low‐cost process leads to homogeneous microstructures with improved material properties compared with the state of the art in continuous fiber‐reinforced oxide/oxide composites. The developed composites in the present study exhibit favorable mechanical properties both at room temperature and after thermal aging for 1000 h at temperatures up to 1300°C.

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room temperature, resulting in mechanical collapse of the coating. This loss of mechanical integrity could also be promoted by massive internal oxidation of the CrN skeleton and, thus, formation of brittle Cr oxides. ConclusionsThe aim of this work was the verification of the high-temperature lubrication concept of CrN coatings containing Ag (Ag contents of 12 at.% and 22 at.%, respectively). As-deposited coatings show a phase-separated structure consisting of CrN and Ag grains with domain sizes of 15±25 nm and 5±10 nm, respectively. The friction coefficient against alumina at room temperature increases slightly from 0.4 to 0.5 with higher Ag contents. Also wear is pronounced in case of higher Ag contents, which is related to the lower hardness of these coatings. During annealing at 600 C, Ag agglomerates form on the coating surface and decrease the friction coefficient to 0.2 at the beginning of the test. With increasing sliding distance, the value increases to 0.40±0.44. This increase is attributed to fast out-diffusion of Ag and, in turn, a quick consumption of the lubricating phase. The remaining porous CrN skeleton lacks sufficient resistance to wear, causing the formation of abrasive debris and the rapid coating degradation after the Ag reservoir is exhausted.Finally, it can be concluded that alloying CrN coatings with Ag offers a high potential to enhance the tribological behavior in a wide temperature range and under varying environmental conditions, provided that the supply of the sliding contact with the Ag lubricant is controlled thoroughly.

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