Casting of Fe-CrMnNi and ZrO2-Based Metal-Matrix Composites and Their Wear Properties

Metal-matrix composites (MMCs) are of high interest due to their combination of a ductile matrix with a hard phase for reinforcement. Besides the production via one of the various powder-metallurgical routes, it is also possible to cast MMCs by infiltrating a porous ceramic structure with liquid melt. In the presented work, the infiltration of a macroporous ceramic through gravity casting is described. The MMC described consists of high-alloyed metastable austenitic-martensitic CrMnNi-cast steel and a metastable zirconium dioxide ceramic. Both materials are able to transform martensitic if load is applied. To increase infiltration of the zirconia foam, sulfur has been added to the steel melt. After the casting, the wear behavior during three-body abrasive wear test of the MMC is examined. The MMC as well as the TRIP steel by itself shows a high improvement in wear resistance, when compared to other wear materials. In order to investigate the increased wear resistance, an XRD-evaluation is described. The amount of alpha'-martensite and ferrite changes from 26 to 97 vol% due to abrasive wear while no transformation of the metastable tetragonal Mg-PSZ can be observed.