MOLYBDENUM AND THE EFFECTS OF MINOR ADDITIONS OF YTTRIUM

Technical Report · Mon Jan 01 04:00:00 EST 1962

OSTI ID:4731362

Klodt, D T; Miller, C S; Nachman, J F

The effects of additions of yttrium as a scavenger of the interstitial oxygen and grain-boundary oxides in molybdenum were studied. Continuously cast small-diameter molybdenum ingots were prepared by melting compacted powder charges of the base metals and yttrium hydride in a non-consumable electrode arc furnace under an argon atmosphere. The soundness and structare of the ingots were improved when the argon pressure was reduced to approximately 50 mm Hg. The ingots were machined to remove surface imperfections and then swaged into rods from which impact specimens were prepared. A recrystallization study was conducted, and all specimens were given a 1-hr recrystallization anneal prior to final machining. Impact tests were made over a range of temperatures and the ductile-to-brittie transition temperature determined. The ductile-to-brittle transition temperature of a 99.2 wt% Mo--0.8 wt% Y alloy was lowered by approximately 200 deg C compared to the unalloyed molybdenum prepared by the same techniques. Retention of yttrium in the molybdenum after arc melting was of the order of 5% of the amount added. (auth)

• Research Organization: Denver. Univ. Denver Research Inst.
• NSA Number: NSA-17-008811
• OSTI ID: 4731362
• Report Number(s): NP-12481
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ARGON
ATOMS
CASTING
DEFECTS
ELECTRIC ARCS
ELECTRODES
FURNACES
GRAIN BOUNDARIES
INTERSTITIAL ATOMS
MACHINING
MELTING
METALS, CERAMICS, AND OTHER MATERIALS
MOLYBDENUM ALLOYS
OXIDES
OXYGEN
POWDERS
PRECIPITATION
PREPARATION
PRESSURE
RECRYSTALLIZATION
RODS
TEMPERATURE
TENSILE PROPERTIES
TRANSITION TEMPERATURE
YTTRIUM ALLOYS
YTTRIUM HYDRIDES