Accession Number : AD0865838

Title :   Synthesis and Characterization of Molybdenum Intermetallic Compounds.

Descriptive Note : Technical rept.,

Corporate Author : CLIMAX MOLYBDENUM CO OF MICHIGAN ANN ARBOR

Personal Author(s) : Dahl, J. ; Semchyshen, M.

Report Date : 01 JAN 1970

Pagination or Media Count : 41

Abstract : Results are reported of investigations on the solubility of cobalt or nickel in the molybdenum-rhodium hexagonal-close-packed compound, on the grain boundary phases observed in the molybdenum plus platinum-group metal hexagonal-close-packed compound, and on a preliminary characterization of the Laves phase Mo2Zr. Based on a starting composition of 62% Rh - 38% Mo, two ternary alloys of the hexagonal-close-packed compound were synthesized: 40% Mo, 36% Rh, 24% Co and 44% Mo, 40% Rh, 16% Ni. The hardnesses of both of the ternary alloys range from 525 DPH at room temperature to about 25 DPH at 1600 C (2912 F). The Mo-Rh-Co alloy has a liquidus range of 1670 to 1745 C (3038 to 3153 F), whereas the Mo-Rh-Ni alloy has a liquidus range from 1630 to 1720 C (2966 to 3128 F). Details of the procedure for extruding the Mo-Rh-Co alloy are discussed. Results are presented on the fractograph examination of several compositions of the hexagonal-close-packed intermetallic compound. It is suggested that phases found in the grain boundaries may contribute to the brittleness of the compound, but evidence is also presented to show that at least the Mo-Ir compositions may be inherently brittle. The procedures for preparing the Laves phase Mo2Zr are presented as are data on the hardness of the compound between room temperature and 800 C (1472 F). The hardness of this compound ranges from 550 DPH at room temperature to 460 DPH at 800 C (1472 F). (Author)

Descriptors :   *INTERMETALLIC COMPOUNDS), (*MOLYBDENUM ALLOYS, (*HEAT RESISTANT ALLOYS, INTERMETALLIC COMPOUNDS), COBALT ALLOYS, NICKEL ALLOYS, PLATINUM ALLOYS, PHASE STUDIES, RHODIUM ALLOYS, SYNTHESIS(CHEMISTRY), HARDNESS, SOLID SOLUTIONS, HIGH TEMPERATURE, IRIDIUM ALLOYS, ZIRCONIUM ALLOYS, LIQUID METALS, FRACTOGRAPHY, BRITTLENESS, GRAIN BOUNDARIES, GRAIN STRUCTURES(METALLURGY), CRYSTAL LATTICES, EXTRUSION, (U)EXTRUSION.

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE