DETERMINATION OF THE SOFTENING POINT OF MIXTURES IN THE BERYLLIUM-BORON SYSTEM AT THE BERYLLIUM-RICH REGION

Journal Article · Fri Jul 01 04:00:00 EDT 1960 · Zhur. Priklad. Khim.

OSTI ID:4153077

Markovskii, L Ya; Markevich, G S

The phase diagram of the Be--B system was investigated up to 50 at.% boron by sending an electric current through the compacts and determining their softening points from the observed bending moments, while the temperature was measured by means of a microoptical pyrometer with a precision of plus or minus 5 deg C. Composition of the specimens was ascertained by x-ray diffraction and chemically by periodate oxidation. The semiconducting properties of BeB/sub 2/ and the high electrical resistance of the mixtures beyond BeB/sub 6/ precluded the use of the above-mentioned method, but extrapolation of data appears to be in agreement with previously published results. It is concluded from the data that the melting point of the mixtures lie about 70 to 80 deg C above the measured softening points. Comparing the results with metallographic observations, it is concluded that the eutectic composition, at about 11 at.% boron, represents the minimum on the temperature vs. boron concentration graph, whereas the maxima at 16.5 and 33.0 at.% boron represent chemical compounds. According to x-ray diffraction studies, the eutectic consists of metallic beryllium and the delta - phase. (TTT)

• Research Organization: State Inst. of Applied Chemistry, USSR
• NSA Number: NSA-14-024617
• OSTI ID: 4153077
• Journal Information: Zhur. Priklad. Khim., Journal Name: Zhur. Priklad. Khim. Vol. Vol: 33
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

BERYLLIUM
BERYLLIUM OXIDES
BORON
CURRENTS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ERRORS
EUTECTICS
HEATING
MEASURED VALUES
MELTING POINTS
METALS, CERAMICS, AND OTHER MATERIALS
PHASE DIAGRAMS
PYROMETERS
QUANTITATIVE ANALYSIS
QUANTITY RATIO
SEMICONDUCTORS
TEMPERATURE
THERMOMETERS
X RADIATION