Accession Number : AD0482508

Title :   RESEARCH AND DEVELOPMENT OF NEW AND IMPROVED CUTTING TOOL MATERIALS.

Descriptive Note : Interim engineering progress rept. 1 Jan-31 Mar 66,

Corporate Author : CARBORUNDUM CO NIAGARA FALLS NY

Personal Author(s) : Whitney, E. Dow ; Murata, Yorihiro ; Julien, H. Paul ; Giese, Rossman F., Jr.

Report Date : APR 1966

Pagination or Media Count : 65

Abstract : Results are presented of effort undertaken to develop new cutting tool materials for machining refractory metals for aerospace applications. The report discusses development of techniques for fabrication of experimental cutting tool inserts from promising carbide, nitride, and boride systems, as well as the results of cutting tests employing various alumina-base tool compositions. Dense bodies having fine grain size were obtained through the hot pressing of niobium diboride plus additive systems. Titanium mononitride was found to be an effective inhibitor of grain growth in niobium diboride. A study of microstructure in the system NbB2-TiN indicated that addition of up to 10 wt. % titanium nitride to niobium diboride resulted in a uniform fine structure after hot pressing. Extensive parameter studies were conducted on alumina-base cutting tool materials with five carbides, four nitrides and six borides as additives. Examination of microstructure, mechanical properties and densification of the hot pressed bodies indicated that tungsten carbide and silicon carbide improved the mechanical strength and microstructure of hot pressed alumina. As a result of this investigation, three new promising cutting tool materials, NbB2-TiN, Al2O3-WC and Al2O3-SiC, were developed. Belt-type ultrahigh pressure, high temperature equipment for material synthesis studies was obtained and is being placed in operation. (Author)

Descriptors :   *NIOBIUM COMPOUNDS), (*CUTTING TOOLS, (*TITANIUM COMPOUNDS, CUTTING TOOLS), CARBIDES, NITRIDES, BORIDES, MACHINING, REFRACTORY METALS, GRAIN STRUCTURES(METALLURGY), ADDITIVES, DENSITY, NITROGEN, GRAIN SIZE, HARDNESS, TUNGSTEN ALLOYS, SILICON ALLOYS, HIGH PRESSURE, HIGH TEMPERATURE, MICROSTRUCTURE, ALUMINUM, OXIDES, MECHANICAL PROPERTIES, TANTALUM ALLOYS, TANTALUM COMPOUNDS.

Subject Categories : Properties of Metals and Alloys
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE