Technology for coating ZrO2/Fe2O3 composite film on surface of diamond by sol-gel method

Abstract

The invention discloses a technology for coating a ZrO2 / Fe2O3 composite film on the surface of diamond by a sol-gel method. The technology comprises the following steps of preparing stable Fe2O3 sol by FeCl3 hydrolysis, dipping a diamond abrasive subjected to surface treatment into the Fe2O3 sol, carrying out drying and calcination on the diamond abrasive to obtain a diamond abrasive of which the surface is uniformly coated with a Fe2O3 film, preparing stable ZrO2 sol by ZrOCl2 hydrolysis, dipping the diamond abrasive of which the surface is uniformly coated with the Fe2O3 film into the ZrO2 sol, and carrying out drying and calcination on the diamond abrasive to obtain the diamond abrasive coated with the ZrO2 / Fe2O3 composite film. The ZrO2 / Fe2O3 composite film can prevent the diamond abrasive from a harmful chemical reaction with a ceramic binder in sintering, improve wettability of the diamond abrasive and the ceramic binder, improve the diamond abrasive holding capacity of the ceramic binder, and prolong a service life of a diamond ceramic grinding tool.

Description

technical field [0001] The invention relates to a diamond abrasive surface modification technology, in particular to a ZrO coating on the diamond surface by a sol-gel method. 2 / Fe 2 o 3 Composite film process. Background technique [0002] Diamond is the hardest substance among all materials, so it is often used to make processing tools. However, synthetic diamonds are mainly in the form of particles and powders, which must be combined with a material called a binder and prepared into a tool with a certain shape and strength. Commonly used binder materials are metals, resins and ceramics. Among them, the vitrified bonded diamond grinding wheel has the characteristics of high elastic modulus, stable chemical properties, water resistance, heat resistance, acid resistance, low cost, strong self-sharpening, and small grinding force. It is especially suitable for non-metallic materials or composite materials. Precision grinding. However, compared with the commonly used res...

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Problems solved by technology

However, the coated metal film is very easy to react with the vitrified bond during the sintering process of the ceramic abrasive, so that the bonding strength between the bond and the diamond abrasive does not increase much.

[0004] Some people also used the sol-gel method to coat TiO on the diamond surface. 2 Thin films and TiO 2 / Al 2 o 3 film, the oxidation resistance of diamond abrasives treated by this process has been greatly improved, but TiO 2 It is difficult for the film to form a bond with the diamond matrix, and the bonding force between the film and the diamond is low; at the same time, TiO 2 The wettability with the vitrified bond is not very good; Al 2 o 3 Although the wettability of the film with the vitrified bond is good, it will chemically react with the alkali metal oxide in the vitrified bond during the sintering process of the vitrified bonded diamond grinding wheel to form an alumina octahedron, which dissolves in the ceramic In the bond, the protective performance of the diamond abrasive is limited, so the bonding strength between the diamond abrasive and the ceramic bond is not greatly improved after coating

Additionally, TiO was coated using the sol-gel method 2 / Al 2 o 3 For thin films, aluminum isopropoxide is used as an organic precursor, and the production cost is also high

In addition, sol-gel technology was used to coat TiO on the surface of diamond abrasives. 2 and TiO 2 / Al 2 o 3 Thin film, the anti-oxidation performance of the diamond abrasive after coating has been greatly improved, but the bonding force between the film and the diamond substrate and the film on the surface of the diamond abrasive and the vitrified bond is weak, and the use of the vitrified bonded diamond grinding wheel cannot be greatly improved. life

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