NITRIDING PROCESS MODERNIZATION ON THE EXAMPLE OF CHOSEN PARTS FROM AIRCRAFT ENGINE

摘要

World industry increasingly takes advantage in nitriding process to produce technological surface layer (TSL) of machine and device components working in conditions of high contact loads. In industry practice not only the traditional gas nitriding has found application, but also whole range of its modern modifications which lets to shape the TSL structure in arbitrary way. Application of ion nitriding has let (by the control of conditions of the process steering) the thickness limiting of the zone of compounds on the surface or even its total elimination. Thanks to this it is possible to limit the allowance for the necessary, costly and the time consuming finish machining like grinding operation or even resigning of carrying it out. As the effect it will result not only in the considerable savings, but also proper stresses distribution of the internal stresses in nitrided layer, what is particularly important in components which are used in the aviation. Additional advantage of this method is also considerable shortening of the time of the nitriding itself and also the energy-saving process, what unquestionably will have the impact on production cost reduction. Modernizing the traditional nitriding process by substituting it with ion nitriding will allow to eliminate the copper plating operation in manufacturing process. This galvanizing process is used in selective protection against nitriding. Copper plating is particularly expensive, energy and water consuming, threat-creating to the natural environment. Due to this not only the production cost will be reduced but it will also considerably limit usage of substances dangerous for the natural environment and maintenance - such as chromic acid anhydride. Usage of chromic acid anhydride as per directive of European Parliament will be prohibited by the 1st of January 2012. In work the examples of modernizing of the nitriding process were discussed on chosen parts having the application in the aviation. The economical analysis has also been presented as well as ecological and legal aspects which argue for the modifications implementation to technological process used up till now. The investigation results acknowledged possibilities of practical use of proposed processes in industry practice.