Improvement of Overhauling process of Outer Casing of Turbojet Engine by Improving the TIG welding parameters and changing of NDT Technique

Abstract

This research deals with the improvement of overhauling process of Outer Casing of a Turbojet Engine by improving the welding parameter to reduce defects and produce reliable quality weld as well as changing of a non destructive testing technique in which conventional radiography testing technique is changed with the digital real time radiography testing with maintaining same of higher sensitivity. The paper covers detailed steps to apply design of experiment (DOE) on TIG welding parameters to find optimized parameters for welding. A 2K full factorial approach was used followed by analysis of results. Study focuses on improving the quality weld with minimize probability of creating any weldment or Heat Affected Zone (HAZ) cracks. The paper also cover the changing of a NDT technique, in which a time consuming conventional radiography testing technique is replaced with digital real time radiography testing technique while maintaining the sensitivity level of the film. Previously aerospace industry giants were reluctant to use RTR, however sensitive panel made this application possible to apply on aerospace parts where higher sensitivity is paramount. Now real time radiography is the first option where speed and accuracy is required to detect subsurface cracks without compromising the sensitivity that is produced by a quality film X-ray image. In this paper Amorphous Silicon detector was used to reproduce the results and compare the results produced by the conventional radiography testing. For verification of sensitivity, Image Quality Indicator (IQI), Penetrameter and known defect sample were successfully reproduced. In future Automatic defect recognition system can be produced and programming can be done to minimize the time where series