Paweł Rokicki

Rapid prototyping in manufacturing of core models of aircraft engine blades

Purpose – The purpose of this paper is to present the advantages of computer-aided design/rapid prototyping (CAD/RP) usage in designing and manufacturing of the core models used for precise casting with direct and single solidification of aircraft engine turbine blade cores. Design/methodology/approach – The process of modelling three-dimensional CAD geometry of research blade in relation to the model of the core was presented with different wax types used in the RP technique. Findings – The geometry of the blade model has been designed in a way which allows making a silicon mould on the basis of a base prototype in the process of rapid tooling (RP/RT). Filing by different wax types was investigated in mean of the impact on filling accuracy of the mould cavity. Originality/value – The resulting models were used to make ceramic moulds and carry further work on the development of casting technology in the process of directional solidification and single crystal solidification of core blades of aircraft engines.

Manufacturing of aircraft engine transmission gear with SLS (DMLS) method

Purpose The purpose of this paper is to present the methodology for manufacturing of aircraft transmission gears using incremental method of rapid prototyping (RP) – direct metal laser sintering (DMLS). The production of prototypes from metallic powders using described system allows the execution of final elements of complex structures with additional economic impacts. Design/methodology/approach The paper describes the use of selective laser sintering method (DMLS) by EOS Company. Whole chain of production of prototype is presented with the addition of geometric accuracy measurements by blue light laser device. Findings Presented in the research analysis of SLS/SLM technologies as rapid manufacturing systems shows that they can be applied in the production of prototypes used in the manufacturing process of gears for propulsion systems in aviation industry. Also, very important is the geometrical accuracy of gear prototypes produced by incremental methods. It determines subsequent treatment steps for aircraft propulsion system gears. Practical Implications The use of RP techniques as an alternative for conventionally used manufacturing method has mainly an economic impact related to the cost of time-consuming process and amount of defected elements appearing in serial production. Originality/value This paper presents possibility to use RP – DMLS system – for propulsion elements of aircraft structure. This research is original because of the complex description of the whole chain of manufacturing process. Additionally, geometrical accuracy measurement methodology by blue light presented with the RP method of manufacturing gives the research a unique characteristic.

The assessment of geometric accuracy of aircraft engine blades with the use of an optical coordinate scanner

Purpose The purpose of this paper is to present coordinate measuring system possibilities in the meaning of the geometric accuracy assessment of hot zone elements in aircraft engines. The aim of the paper is to prove that this method, which uses blue light and is most sufficient and cost-saving method, can to be used in the production line for serial manufacturing of elements, for which a high level of accuracy is required. Design/methodology/approach The analysis of the geometric accuracy of the blades was performed using non-contact optical coordinate scanner ATOS Triple Scan II Blue Light, manufactured by GOM Company, at the Department of Mechanical Engineering, Rzeszow University of Technology. Geometric analysis was conducted for blades manufactured from different waxes (A7Fr/60 and RealWax VisiJet CPX200), thus comparing injection technique and rapid prototyping (RP) method, and for casting made of Inconel 713C nickel-based superalloy. Findings The analysis of the criteria for the method of blades’ measuring selection showed that the chosen system successfully met all criteria for the verification of blades’ geometry at the selected stages of the process. ATOS II optical scanner with blue light technology allows measurement almost regardless of daylight or artificial (white) light. This allows the application of the measurement system in the production cycle, thus eliminating the need to create special conditions for measurements. Practical implications Requirements related to the accuracy of measured values, diversity and allowable measurement time are linked with the methods of production. Modern manufacturing methods based on computer-aided design systems/manufacturing/engineering systems require a non-contact optical measurement method based on the computer-aided-based coordinate measuring technique. In case of the non-contact optical scanning method based on the ATOS GOM measuring system, time and measurement costs depend on the methodology of measurement and the possibility of its automation. This is why the presented paper has a practical impact on possibilities for the automation of geometric accuracy measurements of obtained elements in the series production line. Social implications The use of ATOS Triple Scan II Blue Light by GOM Company allows the reduction of cost and time of production because of the possibility of the introduction of this system in an automated production line. Additionally, the measurement of hot section blades of aircraft engines by using the blue light method is much more accurate and has implication as it impacts safety of further used manufactured elements. Originality/value This paper presents the possibility of using the ATOS Triple Scan II Blue Light measuring system for geometric accuracy measurements in case of hot section blades of aircraft engines. This research is original because it describes three model geometric accuracy measurements, wax model obtained using the injection technique, wax model obtained using the I RP process and casting made of Inconel 713C nickel-based superalloy.

Development of Nickel Based Superalloys for Advanced Turbine Engines

Superalloys have been developed for specific, dedicated properties and applications. One of the main application for this material is advanced, high-performance aircraft engines elements. Turbine engine creates harsh environments for materials due to the high operating temperature and stress level. Hence, as described in this article, many alloys used in the turbine section of these engines are very complex and highly optimized. This article provides an overview of structural changes that occur during the aging process of wrought and cast alloys and provides insight into the use of precipitated particles to achieve desired structures. Example will focus on alloy Inconel 718 and CMSX-4. Functional properties of these alloys can be achieved by choosing proper heat treatment parameters to obtain required rate between secondary phases. The paper also attempts to determine structural perfection and changes of crystallographic orientation along the axis of growth of single crystal nickel superalloys cast using X-ray topography and Laue diffraction method. Single crystal bars and turbine blades were manufactured in VIM furnace using the Bridgeman method. Withdrawing rates typical for CMSX-4 superalloy were used. It has been found that with increasing withdrawing rate the nature of distribution along the axis of growth of the angle of [001] direction deviation from the axis of single crystal blades growth had changed. The change of the withdrawing rate results also in the rotation of γ’ phase in the form of cubes against the axis of single crystal blades growth.

Process Temperature Effect on Surface Layer of Vacuum Carburized Low-Alloy Steel Gears

Gears, due to their complex shape, carried load and required accuracy are ones of most complex aircraft engine parts. Single tooth damage usually breaks the power transmission and causes failure of the entire gear system. Adequate sustainability and guarantees of transmission is therefore a condition for secure operation of whole device. Particularly high requirements for reliability are put to transmissions used in the aerospace industry. Due to the loads which are transmitted through the gears, the materials used by the manufacturer must have not only high strength but also show the abrasion resistance of the surface layer and the ductility of the core. Thermo-chemical treatment of industrial gears is a fundamental process, which gives them adequate mechanical properties regarding loads they carry and the surface conditions of work. The most promising method in the discussed field is vacuum carburizing, which by its specification of work significantly reduce the emission of CO2 and the duration of the process, without reducing the quality of the final product. The main aim of the paper is to present criteria for selection of carburizing parameters (mainly temperature increase) as a part of thermo-chemical treatment process performed using vacuum methods. Proper (higher to compare with conventional methods) carburizing process temperature is crucial in programming of carbon diffusion process meaning in process time and final carburized layer characteristics as carbon profile and homogeneity of the carburized layer.

Dynamic precipitation of nickel-based superalloys undergoing severe deformation below the solvus temperature

Abstract The authors performed uniaxial compression tests of nickel-based superalloys: single crystal CMSX–4, also precipitation hardened; Inconel 718 and X750, at temperatures below the γ′ solvus, in order to study the effect of temperature and strain rate on their flow stress and microstructural development. On the basis of the obtained flow stress values, the activation energy of a high-temperature deformation process was estimated. Microstructural observations of the deformed samples at high temperatures, previously solution heat treated and aged CMSX–4 and Inconel alloys revealed non-uniform deformation effects. Distribution of either molybdenum- or niobium-rich carbides was found to be affected by localized flow within the investigated strain range at relatively low deformation temperatures, 720–850 °C. Microstructural examination of the alloys also showed that shear banding and cavity growth were responsible for the decrease in flow stress and a specimen fracture at larger strains.

Single-frequency induction hardeningof structural steel

Purpose: Current paper presents investigation of specimens after single frequency induction hardening process. The main aim is to compare microstructure of the material after the process conducted with different voltage on the induction coil. Moreover, two different steel grades are used for comparative reasons. As the final result it is desired to obtain sufficient parameters for the process in aim to obtain proper surface treatment of the material. Design/methodology/approach: The objectives of the research are achieved by using single-frequency induction hardening device with varying voltage. Two different steel grades were treated with change of the induction voltage from 300 to 600 V. Findings: In the outcomes of the study, the main conclusion is that there is an impact of the induction voltage in the hardening process on the microstructure of treated elements, both for 40H41Cr4 and 40HNMA36NiCrMo16 steels. Research limitations/implications: Obtained results will be used for much more complex investigation of the induction hardening process in future to introduce more exact parameters and double-frequency induction hardening process for complex geometries as gears. Originality/value: The originality of the research is based on the specific process and the materials that are being submitted to the comparative analysis. Moreover, executed research will be a basis for more complex induction hardening processes in the future.

Investment Casting Design and Processing for Drone’s Micro-Engine Turbine Rotor Manufacturing

The research presents methods for modern design and processing tools to be used in manufacturing process of castings in the aviation industry. In the study it is described how to use a computer simulation software and rapid prototyping / rapid tooling methods for manufacturing of drone’s micro-engine turbine rotor. The computer simulation of flow and solidification process and the investment casting technology were applied for manufactured elements.

The Properties of Refined Glasses with Aluminum Hydroxide Nano-Molecules

New refining technology of soda – calcium – silicon glass surfaces with inorganic compounds nanomolecules has been presented in the study. In order to determine modification of the glass surface SEM observation and EDX analysis have been carried out. The glass samples were subjected to the UV-VIS, photo-elasticity and ellipsometry examinations. From obtained results follows, that refining of the glass surface by nanopowder aluminum hydroxide compounds provides forming of very thin surface layers. This type of modification improves physical glass properties. As the example results of microhardness refined glass are presented in the article.Keywords: glass, surface, nanoparticles, refining

The Surface Morphology and Optical Properties of Refined Glasses with Inorganic Nano-molecules

Abstract New refining technology of soda-calcium-silicon glass surfaces with inorganic compounds nano-molecules has been presented in the study. In order to determine modification of the glass surface SEM observation and EDX analysis have been carried out. The UV-VIS, photo-elasticity and ellipsometry examinations were carried out on glass samples. The results of investigations that have been conducted show that refining process of the glass surface by use of nanopowder inorganic compounds deposited electrostatically on glass surface provides forming of very thin (about 50 nm) surface layers [1]. This method of surface modification improves physical and chemical glass properties. In this paper results of microhardness test of refined glass were also presented.