Abstract: Shaped articles of polycrystalline aluminum nitride are disclosed having a tensile strength of at least about 100 Kpsi. The shaped articles are preferably fibers. Composites of polycrystalline AlN fibers in a matrix of organic or inorganic polymer, metal, glass or ceramic are also disclosed herein. The process for the preparation of polycrystalline aluminum nitride fibers is covered.

Abstract: Zirconium and hafnium boride precursor complexes are prepared by deposition from solution, and yield metal borides upon heating at mild temperatures and ambient pressure.

Abstract: A catalyst composition is disclosed which consists essentially of an aluminum fluoride prepared by the reaction of aluminum hydroxide and HF. Also disclosed is a process for preparing 1,1,-dichloro-1,2,2,2-tetrafluoroethane by chlorofluorination which comprises the step of contacting a gaseous mixture comprising at least one tetrahaloethylene having the formula C.sub.2 Cl.sub.4-x F.sub.x wherein x is an integer from zero to 3 and both Cl.sub.2 and HF with said catalyst composition at an elevated temperature; and a process for producing 2-chloro-1,1,1,2-tetrafluoroethane and/or 1,1,1,2-tetrafluoroethane by hydrodechlorinating 1,1-dichloro-1,2,2,2-tetrafluoroethane prepared by said chlorofluorination.

Abstract: A process is disclosed for transforming a saturated reactant (e.g. 1,1,2-trichloro-1,2,2-trifluoroethane) into a saturated product (e.g. 1,1-dichloro-1,2,2,2-tetrafluoroethane) by contacting a gaseous mixture comprising said reactant with an aluminum fluoride catalyst at an elevated temperature, which is characterized using a catalyst composition consisting essentially of an aluminum fluoride prepared by the reaction of aluminum hydroxide and HF. Also disclosed is a process for producing 2-chloro-1,1,1,2-tetrafluoroethane and/or 1,1,1,2-tetrafluoroethane by hydrodechlorinating 1,1-dichloro-1,2,2,2-tetrafluoroethane produced by said transformation.

Abstract: A process for preparing chemically stable compositions of tetra(hydrocarbyl)metallic compounds in solution, and an improved process for the preparation of active 1-olefin polymerization catalysts.

Abstract: Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RAlNH, followed by heating the spheres or flakes of RAlNH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RAlNH are formed by (i) freezing a suspension of RAlNH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RAlNH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAlNH in a liquid medium and removing frozen medium from the frozen suspension.

Abstract: Shaped articles of polycrystalline AlN and AlN-containing composites; the AlN articles having thermal conductivities of at least about 70 W/mK (watts/meter .degree.K); the AlN component effecting good thermal conductivity in the composited articles.

Abstract: An organoaluminum polymer formed from R.sub.3 A1 and dialkylaluminum amide that is useful for forming shaped articles of inorganic aluminum nitride alone or with nitrides (other than AlN), oxides, borides, carbides or combinations thereof; R being selected from hydrogen; C.sub.1 to C.sub.10 alkyl; halogen; and substituted or unsubstituted phenyl, naphthyl and biphenyl; no more than two of the R groups being alkyl.

Abstract: A method of producing coatings of boron nitride on substrates by the application of solutions containing boron compounds.

Abstract: A process for forming polysilanes from silicon hydrides by contacting the silicon hydride with catalytic amounts of selected scandium, yttrium and rare earth metal hydrides, and a process for hydrosilation of alpha-olefins in which an alpha-olefin is contacted with a silicon hydride in the presence of catalytic amounts of selected scandium, yttrium and rare earth metal compounds.

Abstract: Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RA1NH, followed by heating the spheres or flakes of RA1NH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RA1NH are formed by (i) freezing a suspension of RA1NH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RA1NH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAINH in a liquid medium and removing frozen medium from the frozen suspension.

Abstract: Admixing an aluminum alkyl, and optionally a boron compound, with a hydride of nitrogen in the gas phase and maintaining a gas phase temperature, optionally in the presence of a carrier gas, and producing aluminum nitride alone or in admixture with a precursor thereof or boron nitride or both.

Abstract: Cross-linked organosilazane polymers which are useful as ceramic precursors and film casting are disclosed.

Abstract: An organoaluminum polymer formed from R.sub.3 Al and R.sub.2 AlNH.sub.2 that is useful for forming shaped articles of inorganic aluminum nitride along or with other nitrides, oxides, carbides or combinations thereof; R being selected from C.sub.x H.sub.2x+1 wherein x is 1 to 10.

Abstract: Alkali-metal tetraorganylborate compounds of formula MBR.sub.4 are prepared by reacting triorganylboranes R.sub.3 B with alkali-metal hydroxide or alkoxide compounds of the formula MOR.sup.1.

Abstract: The oxidation and extraction steps in the vanadium stripping process (e.g., the DEPA-TOPO or DOPPA-TOPO process) are carried out simultaneously for recovering vanadium from wet-process phosphoric acid.