Accession Number : AD0815264

Title :   DEVELOPMENT OF HIGH-STRENGTH MOLYBDENUM- AND TUNGSTEN-BASE ALLOYS.

Descriptive Note : Final rept. 1 Mar 65-1 May 66,

Corporate Author : CLIMAX MOLYBDENUM CO OF MICHIGAN ANN ARBOR

Personal Author(s) : Semchyshen, M. ; Kalns, Eric ; Klaphaak, Daniel J. ; Barr, Robert Q.

Report Date : 30 DEC 1966

Pagination or Media Count : 101

Abstract : Solid-solution-strengthened tungsten-base alloys were vacuum-arc-cast with relatively large additions of tantalum, Columbium, and/or molybdenum. Machined blanks from the ingots were extruded to round bar stock at temperatures from 3600 to 4000 F. Extrusion recoveries varied considerably from heat-to-heat. Elevated-temperature tensile tests were performed on specimens machined from available extruded bar stock. Strengths were well above those reported for unalloyed tungsten, but were below those resulting from earlier studies on dispersion-strengthened tungsten-base alloys. Molybdenum-base alloy sheets were prepared representing two compositions and three thermomechanical histories. Compositions studied were Mo + 1.25% Ti + 0.3% Zr + 0.1% C (TZC), and Mo + 0.3% Zr + 0.03% C. The thermomechanical variables imposed were solution heat treatments at various stages during the working schedules. Recrystallization behavior, bend transition temperatures, and tensile properties were quite sensitive to working schedules. Earlier work at this Laboratory indicated that in-process solution treatments at temperatures sufficiently high to effect increases in tensile strength usually resulted in increased transition temperatures. The present work has shown that a much more favorable trade-off between strength and transition temperature can result from the proper placement of the solution treatment in the working schedule.

Descriptors :   (*TUNGSTEN ALLOYS, HOT WORKING), (*MOLYBDENUM ALLOYS, HOT WORKING), HEAT TREATMENT, EXTRUSION, ROLLING(METALLURGY), ARC MELTING, ADDITIVES, TANTALUM ALLOYS, NIOBIUM ALLOYS, ZIRCONIUM ALLOYS, SOLID SOLUTIONS, DISPERSION HARDENING, RECRYSTALLIZATION, DUCTILE BRITTLE TRANSITION, TENSILE PROPERTIES, DUCTILITY, HAFNIUM ALLOYS, MICROSTRUCTURE, FRACTOGRAPHY, CARBIDES, NITRIDES.

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE