99.99% Rhenium (Re) Pure Metal
Rhenium (Re) is a scattered rare metal, atomic number - 75, atomic
mass - 186.31, density - 21.0 g / cm3, melting point - 3180 ± 20ОС,
coefficient of linear expansion - 12.45.10-5, electrical resistivity Ohm
.m, at
Rhenium is a refractory heavy metal similar in appearance to steel.
Unlike tungsten, rhenium is ductile in the cast and recrystallized state
and can be deformed at room temperature. Rhenium has a very high modulus
of elasticity. After a small degree of reduction, its hardness increases
significantly (from work hardening), but after annealing in a protective
medium - hydrogen or vacuum, it again acquires plasticity.
Rhenium is chemically stable in air at 20 ° C. The compact metal begins
to oxidize with the formation of rhenium hetoxide when heated above 300
° C and the process proceeds intensively at a temperature above 600 ° C.
Fine powders of rhenium are humidified in air, which is explained by
partial oxidation with the formation of rhenium hemioxide, which absorbs
moisture. Rhenium does not react with hydrogen up to the melting point.
Rhenium is significantly more chemically stable than tungsten, in an
argon atmosphere or in a vacuum, in the presence of traces of moisture,
at high temperatures. Rhenium does not react with nitrogen, although
rhenium nitrides are known, which are formed not by the direct action of
nitrogen on the metal, but by the reaction between rhenium chloride and
ammonia. Rhenium does not form carbides, which distinguishes it from
other refractory metals. Rhenium reacts with fluorine and chlorine when
heated, with bromine and iodine, practically does not interact.
APPLICATION.
Despite the fact that rhenium began to be used in industry relatively
recently (after 1950), at present its importance in modern technology is
great and is constantly increasing.
The main fields of application of rhenium are bimetallic catalysts Pt /
Re, and are used in the purification of gasoline to obtain light
fractions — reforming of oil (90%); production of alloys for various
purposes and thin-film coatings.
In addition, rhenium is used in electronics and electrical engineering.
In electrovacuum devices, alloys with different contents of rhenium are
used: tungsten-rhenium, nickel-rhenium, nickel-rhenium-iron,
molybdenum-rhenium and others.
In the electrical industry, rhenium, its alloys and rhenium coatings are
used for the manufacture of thermocouples with a measurement range from
0 to 2500 ° C, self-cleaning electrical contacts, and filaments. Rhenium
is used in switch devices, where the high stability of the
points-supports must be combined with high hardness and the least wear.
Rhenium is used in the rocket and aerospace industries, for the
manufacture of combustion chambers, exhaust nozzles of jet engines, and
turbine blades. Due to its unique qualities of hardness and high heat
resistance of rhenium, it is difficult for these products to be
replaced.
Rhenium is a catalyst for many chemical processes — powdered rhenium and
some of its compounds serve as catalysts in the oxidation of ammonia and
methane, and in the hydrogenation of ethylene.
High prices for rhenium somewhat limit its use.
.
Rhenium (Re) is a scattered rare metal, atomic number - 75, atomic
mass - 186.31, density - 21.0 g / cm3, melting point - 3180 ± 20ОС,
coefficient of linear expansion - 12.45.10-5, electrical resistivity Ohm
.m, at
Rhenium is a refractory heavy metal similar in appearance to steel.
Unlike tungsten, rhenium is ductile in the cast and recrystallized state
and can be deformed at room temperature. Rhenium has a very high modulus
of elasticity. After a small degree of reduction, its hardness increases
significantly (from work hardening), but after annealing in a protective
medium - hydrogen or vacuum, it again acquires plasticity.
Rhenium is chemically stable in air at 20 ° C. The compact metal begins
to oxidize with the formation of rhenium hetoxide when heated above 300
° C and the process proceeds intensively at a temperature above 600 ° C.
Fine powders of rhenium are humidified in air, which is explained by
partial oxidation with the formation of rhenium hemioxide, which absorbs
moisture. Rhenium does not react with hydrogen up to the melting point.
Rhenium is significantly more chemically stable than tungsten, in an
argon atmosphere or in a vacuum, in the presence of traces of moisture,
at high temperatures. Rhenium does not react with nitrogen, although
rhenium nitrides are known, which are formed not by the direct action of
nitrogen on the metal, but by the reaction between rhenium chloride and
ammonia. Rhenium does not form carbides, which distinguishes it from
other refractory metals. Rhenium reacts with fluorine and chlorine when
heated, with bromine and iodine, practically does not interact.
APPLICATION.
Despite the fact that rhenium began to be used in industry relatively
recently (after 1950), at present its importance in modern technology is
great and is constantly increasing.
The main fields of application of rhenium are bimetallic catalysts Pt /
Re, and are used in the purification of gasoline to obtain light
fractions — reforming of oil (90%); production of alloys for various
purposes and thin-film coatings.
In addition, rhenium is used in electronics and electrical engineering.
In electrovacuum devices, alloys with different contents of rhenium are
used: tungsten-rhenium, nickel-rhenium, nickel-rhenium-iron,
molybdenum-rhenium and others.
In the electrical industry, rhenium, its alloys and rhenium coatings are
used for the manufacture of thermocouples with a measurement range from
0 to 2500 ° C, self-cleaning electrical contacts, and filaments. Rhenium
is used in switch devices, where the high stability of the
points-supports must be combined with high hardness and the least wear.
Rhenium is used in the rocket and aerospace industries, for the
manufacture of combustion chambers, exhaust nozzles of jet engines, and
turbine blades. Due to its unique qualities of hardness and high heat
resistance of rhenium, it is difficult for these products to be
replaced.
Rhenium is a catalyst for many chemical processes — powdered rhenium and
some of its compounds serve as catalysts in the oxidation of ammonia and
methane, and in the hydrogenation of ethylene.
High prices for rhenium somewhat limit its use.
.