ALLOYS OF MAGNESIUM CONTAINING THORIUM

Journal Article · Fri Jan 01 04:00:00 EST 1960 · Trudy Inst. Met., im. A. A. Baikova

OSTI ID:4814389

Drits, M E; Mal'tsev, M V; Sviderskaya, Z A; Padezhnova, E M

Several binary and ternary magnesium-thorium alloys were investigated using additions of manganese, cerium, aluminum, zinc, calcium, and zirconium. The properties of magnesium-thorium alloys anmd also the effects of the additions on the properties at both room and elevated temperature were examined. The alloys were cast in a 20-mm diameter metallic mould heated to 50-60 deg C. The main method of investigating the properties consisted of short-time (30 sec) and long-time (60 min) hardness measurements. The hardnesses were measured at room temperature and 300 deg C using a 10-nmm ball and a 100-kg load. The alloys were stabilized at 300 deg C for 100 hours before testing. Measurements were also made after quenching from 565 deg C. A marked increase occurred in the hardness of magnesium in the cast and stabilized conditions with increase in thorium content to 4%. Further increases in thorium content to 6 - 10% had littie effect. The hardness decreased somewhat after the stabilization treatment. After quenching from 565 deg C, the hardness increased with increasing thorium content up to 10%. The prolonged hardness gave extremely high values. From microstructural and thermal analysis it was shown that the magnesiumthorium system is of the eutectic type. The eutectic consists of alpha -solid solution and the compound Mg/sub 5/Th, melting at 40-42% thorium and 580 deg C. The solubility of thorium at the eutectic temperature is 5% and at 300 deg C, 0.5%. Microhardness measurements showed that the hardness of the compound was 306 kg/mm/ sup 2/, the eutectic was 118 kg/mm/sup 2/, and the solid solution was 74 kg/mm/ sup 2/, corresponding to a hardness for magnesium of 47 kg/mm/sup 2/. The effect of the additions of the various elements was studied using an alloy containing 3% thorium. Cerium had the greatest effect on the properties at room temperature, the hardness continuously increasing up to 6% cerium. Calcium and zinc had a positive effect up to 0.5-1%, further additions showing no change. Low additions of manganese and aluminum gave a decrease in hardness. Funther additions gave an increase. The greatest effect on the prolonged hardness at 300 deg C was shown by 0.6-1% manganese. Cerium also showed an increase, but to a lesser degree. (OTS)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-16-009246
• OSTI ID: 4814389
• Journal Information: Trudy Inst. Met., im. A. A. Baikova, Journal Name: Trudy Inst. Met., im. A. A. Baikova Vol. Vol: No. 4
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALUMINUM ALLOYS
ANNEALING
CALCIUM ALLOYS
CERIUM ALLOYS
DTA
EUTECTICS
EXPANSION
HARDNESS
HEAT TREATMENTS
HIGH TEMPERATURE
IMPURITIES
INTERMETALLIC COMPOUNDS
MAGNESIUM ALLOYS
MANGANESE ALLOYS
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
PHASE DIAGRAMS
QUANTITY RATIO
QUENCHING
SOLID SOLUTIONS
SOLUBILITY
TEMPERATURE
THORIUM ALLOYS
ZINC ALLOYS
ZIRCONIUM ALLOYS