초록 ▼

Refractory borides or carbides are prepared by contacting an alkali-metal reducible metal chloride or silicon tetrachloride with boron trichloride or carbon tetrachloride in an inert solvent in the presence of an alkali metal, the metal chloride or silicon tetrachloride and the boron trichloride or

Refractory borides or carbides are prepared by contacting an alkali-metal reducible metal chloride or silicon tetrachloride with boron trichloride or carbon tetrachloride in an inert solvent in the presence of an alkali metal, the metal chloride or silicon tetrachloride and the boron trichloride or carbon tetrachloride being present in an amount about stoichiometrically equivalent to the boride or carbide to be prepared and the alkali metal being present in an amount about stoichiometrically equivalent to the amount of chloride in the metal chloride or silicon tetrachloride and the boron trichloride or carbon tetrachloride, until all chloride present has reacted with the alkali metal to form alkali metal chloride, separating the inert solvent to leave a solid residue containing a metal boride, silicon carbide or metal carbide precursor together with the alkali metal chloride, and calcining the residue while separating the alkali metal chloride until the precursor is converted to the refractory boride or carbide.

대표청구항 ▼

A method for the preparation of a refractory boride or carbide which comprises contacting a metal chloride, said metal chloride undergoing reduction on reaction with an alkali metal, or silicon tetrachloride with boron trichloride or carbon tetrachloride in a solvent unreactive with said alkali meta

A method for the preparation of a refractory boride or carbide which comprises contacting a metal chloride, said metal chloride undergoing reduction on reaction with an alkali metal, or silicon tetrachloride with boron trichloride or carbon tetrachloride in a solvent unreactive with said alkali metal and said chlorides in the presence of an alkali metal, said metal chloride or silicon tetrachloride and said boron trichloride or carbon tetrachloride being present in an amount about stoichiometrically equivalent to the boride or carbide to be prepared and said alkali metal being present in an amount about stoichiometrically equivalent to the amount of chloride in said metal chloride or silicon tetrachloride and said boron trichloride or carbon tetrachloride, until the aforesaid chlorides present have reacted with the alkali metal to form alkali metal chloride, separating the solvent to leave a solid residue containing a metal boride, silicon carbide or metal carbide precursor together with the alkali metal chloride, and heating the residue at about 700°-900°C. while separating the alkali metal chloride until the said precursor is converted to the refractory boride or carbide.