Papers by Keyword: Hollow Cathode Discharge

Abstract: The discharge of RF hollow cathode far zone plasma has advantages of high ion concentration, easy to implement the processing of a large area, given more and more attention. The characteristics of hollow cathode plasma flow have a great relationship with the hollow cathode nozzle structure. How to design the hollow cathode nozzle discharge structure accurately and conveniently is the key problem of the hollow cathode far plasma surface treatment. This article builds a hollow cathode plasma discharge self-consistent model; derive the relationship between the discharge current of the hollow cathode plasma and the hollow cathode nozzle structure. Optimize the design of the hollow cathode discharge structure using discharge particle simulation software, to achieve a fast and accurate design and the purpose of efficient plasma surface modification.

Abstract: Multilayered TiN coating was successfully prepared by hollow cathode discharge method. By introduction of the multilayered microstructure, the columnar epitaxial growth of TiN grains was obviously suppressed. The hardness, adhesion performance and wear resistance of the multilayered TiN coating were compared with those of the ordinary TiN coating. The wear resistance of the multilayered TiN coating is much better than that of the ordinary TiN coating. It is due to the multilayered microstructure of the coating that pileups the dislocations and also inhibits the bulk-flaking behavior for the multilayered TiN coating. The morphology analysis of cross section shows that the wear mechanism of the multilayered TiN coating is the micro-area detachment. Moreover, the adhesion of the TiN coating to the substrate is greatly enhanced by the microstructure optimization of the coating.

Abstract: Porous materials are successfully utilized for fabrication of many industrial components such as filters and selflubricating bearings. These products are made by powder metallurgy, where mixtured or prealloyed powders can be used. The aluminum bronze is one of the most wanted due its excellent properties in combination with low cost of the raw materials. In this work, single action compacted (100 MPa) prealloyed aluminum bronze (Cu- 9wt%Al-1wt%Fe) cylinders were sintered using a hollow cathode discharge at temperatures between 400 and 750°C with duration on the isotherm for 12 min. Microstructure changes, homogeneity, porosity and composition were analyzed after the treatment. Sintering below 550° C led to uniform but porous structure. Above 550 °C it was observed a solidified central region and a porous structure that changes slightly through out the cross-section. The diameter of the central region increased with treatment temperature. It is concluded that due to the intense plasma heating and subsequent surface melt formation a mass flow direction to the center of compacts occurred.