THE METALLURGY OF YTTRIUM AND RARE EARTH METALS. PART II. MECHANICAL PROPERTIES. Period covered: October 1958 to October 1959

Technical Report · Sat Feb 27 04:00:00 EST 1960

OSTI ID:4032851

Love, B

Study of the mechanical properties of rare earth metals was continued. Tensile, compression, fatigue, and impact properties were determined. Evaluation of the metals was extended to include hot and cold working characteristics, and studies were made of alloy systems predicted to have improved mechanical properties. Cast yttrium, dysprosium, and erbium were cold worked to improve mechanical properties. All were easily swaged at 960 deg C (1800 deg F). The resulting structures were uniform and dense, and the properties were improved over the cast condition. Tensile properties were quite comparable when the metals were in the same condition. Ductility (as measured by reduction of area) was somewhat limited for the cast structures, but was tmproved by working. The cast rare earth metals were notch sensitive. The fatigue properties followed the normal pattern of increased life with decreased maximum applied load. Extrapolated S-N curves indicated fatigue endurance limits in the order of 40 to 50% of the corresponding ultimate tensile strengths. Zirconium entered into solid solution in erbium and resulted in marked tensile strengthening. Dispersed, second phase zirconium, also contributed to hardening. Tbe recrystallization behavior of erbium and yttrium follows a normal sequence of recovery, recrystallization and grain growth. Complete recrystaallization of erbium, cold worked 60%, occurred at approximately 1100 deg C; yttrium at approximately 900 deg C. Studies were made of sevsral methods for improving the purity of rare earth metals. Carbon deoxidation decreased the oxygen contant slightly. Attempts to purtiy yttrium, erbium, and dysprosium by electron beam melting were not successful. Small quantities of both dysprosium and scandium were, however, successfully vacuum distilled at elevated temperatures. Analytic results indicated that the distilled metals are of significantly higher purity. (auth)

• Research Organization: Nuclear Corp. of America. Research Chemicals Div., Burbank, Calif.
• NSA Number: NSA-15-016069
• OSTI ID: 4032851
• Report Number(s): WADD-TR-60-74(Pt.II); AD-24359
• Country of Publication: United States
• Language: English

Related Subjects

ALLOYS
CARBON
CASTING
COLD WORKING
DENSITY
DIAGRAMS
DISPERSIONS
DISTILLATION
DUCTILITY
DYSPROSIUM
ERBIUM
EXPANSION
GRAIN SIZE
HARDNESS
HIGH TEMPERATURE
LATTICES
MEASURED VALUES
MECHANICAL PROPERTIES
METALS
METALS, CERAMICS, AND OTHER MATERIALS
OXIDATION
OXYGEN
PHASE DIAGRAMS
RECRYSTALLIZATION
SCANDIUM
SENSITIVITY
SOLID SOLUTIONS
STRESSES
TENSILE PROPERTIES
VACUUM
YTTRIUM
ZIRCONIUM