Fundamental Studies on Sintering of Alloys, Composites, and Coatings

Oklahoma State University, Stillwater OK

Investigators

Abstract

Sintering is the process of forming engineering components by heating material powder under pressure. Sintering processes are widely used for the manufacturing of metallic, ceramic, and composite components for automotive, aerospace, defense, and machine tool industries. However, it is often very challenging to sinter the components free from processing-related undesirable changes in structure and properties of materials. Controlling the structure of materials during sintering becomes particularly important for highly temperature-sensitive materials such as amorphous alloys. These materials are being considered for several applications due to their outstanding mechanical and electrochemical properties. This award supports fundamental research related to the development of sintering processes for the amorphous alloys and their composites and coatings. The results of this research will lead to innovations in the strategic area of advanced manufacturing of engineering materials, identified as a key to national economic development. The research will also promote the participation of diverse groups of students in manufacturing research. In spite of their attractive properties, actual utilization of amorphous alloys in practical applications has been limited primarily due to difficulties in processing of bulk shapes using conventional solidification processing. The spark plasma sintering process involving simultaneous application of pulsed direct current and uniaxial pressure offers interesting possibilities of manufacturing bulk amorphous alloys without undesirable changes in material structure. The research team will perform experiments to investigate the fundamental mechanisms of densification for the spark plasma sintering of bulk amorphous alloys, particle reinforced and laminated composites, and thick amorphous alloy coatings. The research will elucidate the mechanisms of evolution of nanocrystalline size distribution in amorphous alloys, ductility development in composites, and tribological corrosion behavior of amorphous composite coatings. The major objective is to establish the processing-microstructure-properties correlations in these areas of research. Successful completion of this research would significantly advance the state-of-the-art in spark plasma sintering of amorphous metallic alloys leading to wider industry acceptance of the sintering technology and engineered amorphous materials in a wide range of applications.