Abstract: A method is described for improving the erosion and abrasion wear resistance and hardness of the internal wear surfaces of structures such as nozzles, jets, ducts, chutes, powder handling tubes, valve housings, conveyors, drill bushings and the like. A substantially pure tungsten layer is chemical vapor deposited on the internal wear surface of the body of the structure followed by a chemical vapor deposited top coating comprising a mixture of tungsten and tungsten carbide. The tungsten carbide is selected from the group consisting of W.sub.2 C, W.sub.3 C, and mixtures thereof and is fine grained, non-columnar and has a substantially layered microstructure. Also described are structures formed by the method.

Abstract: Stabilized acicular ferromagnetic chromium dioxide is prepared by reductive treatment of the chromium dioxide with Na.sub.2 [Fe(CO).sub.4 ], and this material is present in magnetic recording media.

Abstract: The present invention provides a novel hydrothermal process for producing zirconia sol comprising the following steps: mixing zirconium acetate with diluted glacial acetic acid to form a zirconium acetate/glacial acetic acid solution, wherein the molar ratio of glacial acetic acid to zirconium acetate as zirconia is in the range between about 7-20; and heating the zirconium acetate/glacial acetic acid solution to a temperature of at least 160.degree. C., thereby forming a zirconia sol.

Abstract: Crystalline zirconium oxide powder with a BET surface of less than 30 m.sup.2 /g, preferably 10 to 20 m.sup.2 /g, a primary particle size of 0.1 to 0.5 .mu.m, a monoclinic crystal structure and, optionally, a content of Y.sub.2 O.sub.3 of 1 to 10% by weight and/or of 1 to 10 % by wt. MgO.It is produced by adding an aqueous zirconium salt solution optionally containing yttrium ions and/or magnesium ions under agitation into a vessel which contains an aqueous base solution such as e.g. sodium hydroxide solution with a content of NaOH which corresponds to an excess of at least 0.5 mole/1 NaOH. The mixture obtained in this manner is then treated hydrothermally at a temperature of 200.degree. to 400.degree. C., the product obtained is separated by filtration, washed chloride-free with water and dried at 100.degree. to 200.degree. C.The zirconium oxide power can be used to produce sintered ceramics.