Device for microwave plasma based low-energy ion implantation on internal surface of metal round pipe with small pipe diameter

Abstract

A device for microwave plasma based low-energy ion implantation on the internal surface of a metal round pipe with small pipe diameter comprises a vacuum chamber (7) and a low-energy ion implantation power supply (10), and belongs to the technical field of material surface engineering. The device is characterized in that: a microwave source (1), a microwave coaxial waveguide inner conductor (2), a microwave coaxial waveguide outer conductor (3), a microwave coaxial waveguide short-circuit piston (5) and an external magnetic field coil (9) form a linear ECR microwave plasma source; by using the excitation and ionization actions of a microwave gap radiation antenna (4), peripheral and axial high-density ECR microwave plasmas distributed uniformly are formed along the central axis of a treated metal pipe (11) under the excitation of an external magnetic field; and by combining low-pulse negative bias applied by the low-energy ion implantation power supply (10) and an auxiliary outer heat source (8) arranged coaxially, the plasma based low-energy ion implantation is finished on the internal surface of the metal round pipe. The device has the advantages of low cost, and capability of implementing the plasma based low-energy ion implantation on the internal surface of the metal round pipe with small pipe diameter and large length-diameter ratio.

Description

technical field [0001] The invention relates to a microwave plasma-based low-energy ion implantation device for the inner surface of a small-diameter metal circular tube, in particular, a linear electron cyclotron resonance (ECR) microwave plasma source is used to implant low-energy nitrogen, carbon, boron and other non-metallic ions into a small-diameter tube. The invention relates to a modification technology of the inner surface of a metal circular tube, which belongs to the field of material surface engineering. technical background [0002] The wear, corrosion and fatigue failure of metal round pipe fittings, especially the small diameter and large aspect ratio round pipe fittings with an inner diameter of 10-30mm, have become a bottleneck problem in the application of petrochemical, mechanical power, marine ships and other engineering fields. For example, oil production machinery, oil pipelines in oil fields, valves and pipelines in chemical industry, and matching part...

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Problems solved by technology

[0010] The purpose and task of the present invention are to overcome the existence of the metal pipe fitting inner surface modification method based on plasma-based ion implantation technology: (1) in order to ensure sufficient ion implantation modified layer depth and improve the quality of the modified layer, it is necessary to use High pulse negative bias voltage higher than 10kV, due to the pulse negative high voltage directly connected to the workpiece, the ion sheath changes in a large range. In order to achieve a uniform implantation effect, a sufficient distance must be kept between the plasma source and the workpiece, resulting in the processing inner diameter The inner surface of metal pipe fittings of 10-50 mm is still limited; (2) plasma-based ions are implanted into the inner surface of small-diameter metal pipe fittings. In order to obtain an effective modification layer depth, a plasma density higher than 10 10 cm -3 The high-density plasma source, the plasma density of the current gate-enhanced DC or RF plasma source is low, which cannot meet the requirements; (3) The secondary electron emission generated by the high pulse negative bias causes a huge waste of device power At the same time, the secondary electrons also bring the disadvantage of strong x-ray radiation, providing a linear ECR microwave plasma source that generates high-density plasma on the central axis of the metal pipe, replacing the low-density DC or radio frequency plasma source, combined with Plasma-based low-energy ion implantation device for inner surface of small-diameter metal circular tube with low-pulse negative bias and auxiliary external heat source

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