4 results about "CHROMIC OXIDE" patented technology

The application provides a metallographic structure display method of a gold-based alloy, and the display method comprises the following steps: taking the gold-based alloy as an anode, electrolytic immersion etching the gold-based alloy in an electrolyte composed of hydrochloric acid, nitric acid and anhydrous ethanol, then cleaning the surface of the obtained gold-based alloy to obtain the gold-based alloy after electrolytic immersion etching; soaking the gold-based alloy after electrolytic immersion etching in ammonia water, then cleaning the surface of the obtained gold-based alloy, and obtaining the gold-based alloy after preliminary treatment after the surface is dried; immersing the gold-based alloy after preliminary treatment in a corrosion liquid composed of a saturated aqueous solution of chromium trioxide, hydrochloric acid and distilled water, then cleaning the surface of the obtained gold-based alloy, and completing the display of the metallographic structure of the gold-based alloy after the surface is dried, which greatly facilitates the observation of the metallographic structure of the gold-based alloy and is beneficial to obtaining the gold-based alloy product meeting the performance requirements.

The invention relates to the technical field of casting or heat treatment coatings, in particular to an anti-oxidation and anti-decarburization coating, a preparation method thereof and special steel. The coating is prepared from the following raw materials: high-temperature-resistant ceramic powder, sepiolite powder, mullite powder, aluminum oxide, chromic oxide, silicon carbide, a binder and water. The coating is rapid in film formation, smooth in surface after film formation and relatively good in leveling property; a layer of compact firm protective film capable of isolating a matrix from a heating atmosphere is formed on the metal surface during heating, so that the oxidation and decarbonization phenomena of the high-speed steel are quickly reduced, and permeation of other elements can be reduced; the influence on the physical and mechanical properties and chemical properties of the protected high-speed steel is small; after heating, cleaning is convenient, and automatic stripping is achieved; sagging does not occur at high temperature, and no toxic gas is generated; and after being coated, the coating has higher adhesive force, and after being heated, the coating also has better stripping property.