Study of the manufacturing accuracy of turbine nozzle blanks manufactured by selective laser alloying technology based on short-term quality control cards

This paper presents the results of a study of the accuracy of manufacturing turbine nozzle sections using the selective laser melting method, based on short-term quality control charts. Turbine nozzle sections were manufactured from Inconel 738 material using selective laser melting with SLM 280HL machine. The geometric characteristics of the turbine nozzle sections manufactured using additive technology were monitored using a coordinate measuring machine. A technique for modifying nominal/target cards is presented that does not increase the length of control cards, regardless of the number of quality characteristics. A statistical process analysis procedure was carried out using short-term control charts for quantitative data and an assessment of the process capabilities and its suitability to meet specified requirements. An indicator chosen as a characteristic of product quality is the accuracy of the profile geometry of the blades of the nozzle section section, which significantly affects the performance characteristics of the product. As a result of the statistical analysis, it was established that the process is in a state of statistical control with respect to internal variability, the process is suitable for meeting the specified requirements and has a sufficient reserve of capabilities necessary to effectively control the progress of the process.