PROCESSING-MICROSTRUCTURE-PROPERTY CORRELATION OF CERAMIC NANOMATERIALS

摘要

Bulk nanoceramic materials, containing nano-phase dispersion (characteristic length scales less than 100 nm) in ceramic matrix composites, have been the subject of considerable research activities in recent years. One of the major challenges in the processing of ceramic nanomaterials lies in the restriction of the grain growth during sintering. Among advanced sintering technique, spark plasma sintering (SPS) has been widely used to process a variety of nanoceramics and nanoceramic composites. The present contribution presents an overview of our recent research results, obtained while developing bulk ceramic nanomaterials. In particular, the processing-microstructure-property relationship of ZrO _2 nanoceramics, ZrO_2-ZrB_2 nanoceramic composite and WC-ZrO_2 nanocomposites is discussed. A comparison has been made with the conventionally sintered materials. The optimization of SPS parameters to obtain the dense ceramic nanomaterials is also reported. Some transmission electron microscopy (TEM) observations, revealing the nanoscaled (< 100 nm) ceramic grains/reinforcements are also reported. An important observation has been that high hardness as well as improved wear resistance can be achieved with the investigated ceramic nanomaterials. The enhancement in mechanical as well as tribological property has been explained from the point of view of microstructural refinement.