Method for depositing high-quality diamond coating on inner wall of tubular workpiece

Abstract

The invention provides a method for depositing a high-quality diamond coating on the inner wall of a tubular workpiece. The method comprises the steps that firstly plasmas are formed inside the tubular workpiece by utilizing electric arc discharge, and then the high-quality diamond coating is deposited on the inner wall of the tubular workpiece by utilizing a strong direct current arc stretching plasma chemical vapor deposition technology. The device involved in the method comprise a diamond coating deposition system composed of a vacuum chamber (1), a ceramic workpiece frame (2), the tubularworkpiece (3), an anode (4), a plasma column (5), a cathode (6) and electromagnetic coils (7), wherein the ceramic workpiece frame (2) is used for insulating the tubular workpiece (3) from the vacuumchamber (1). According to the method for depositing the high-quality diamond coating on the inner wall of the tubular workpiece, the high-density plasmas are formed through arc discharge in the tubular workpiece, so that the surface of the inner wall of the tubular workpiece can form and maintain high-concentration atomic hydrogen; and the high-concentration atomic hydrogen exists so that a sp2 bond of carbon can be completely converted into an SP3 bond, formation of the diamond phase is promoted, and finally the high-quality diamond coating on the inner wall of the tubular workpiece is deposited.

Description

technical field [0001] The invention belongs to the field of diamond coating preparation and relates to a new method for depositing a high-quality diamond coating on the inner wall of a tubular workpiece. Background technique [0002] As we all know, diamond has extremely excellent physical and chemical properties. It is widely used in the fields of machining, wear resistance, corrosion resistance, acoustics, optics and heat conduction. The cost of diamond single crystal is very high, and diamond coating with similar performance has more room for development due to its high cost performance. [0003] The diamond coating is deposited using the plasma chemical vapor deposition technology, which is different from the ordinary plasma-assisted chemical vapor deposition technology in that sufficient atomic hydrogen must exist during the deposition of the diamond coating. This is mainly due to the steady-state sp 2 The hybridized carbon atoms will preferentially form a graphite ...

AI Technical Summary

Problems solved by technology

First, due to the lower concentration of electrons produced by the hot-filament method, a lower concentration of atomic hydrogen is formed

This leads to imperfect etching of atomic hydrogen during diamond nucleation and growth, resulting in more sp in the coating. 2 Hybrid graphitic phase, resulting in poor quality diamond coatings deposited

Second, at high temperature, the metal wire will evaporate in large quantities, and the evaporated metal vapor reacts with carbon to produce metal carbides that enter the diamond coating and cause pollution, which will also significantly reduce the quality of the diamond coating

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