Aluminide Coating Simulations

2016-08-01
Boyraz, Mustafa Tarık
İmer, Muhsine Bilge
Nickel-based super alloys are generally preferred as substrate materials for gas turbine blades due to their high creep resistance and excellent mechanical strength at high temperatures. To improve high temperature oxidation and corrosion resistance ofthese substrate materials, aluminide coatings are typically used as protective coatings, thereby improving lifetimes of advanced gas turbine blades. For clean and pure coating of aluminum at substrate surface, chemical vapor deposition method (CVD) is widely used for turbine blade coatings. The aim of this research is to develop a simulation model using DICTRA that is compatible with experimental CVD operations. After this aim is achieved, the ultimate goal is to use this simulation model to provide input parameters for experimental CVD operations. In this research, two models were compared and named as “Diffusion Couple Model” and “Al Deposition Model”. The “Diffusion Couple Model” simulates diffusion between IN 738LC and Al diffusion couple while the “Al Deposition Model” simulates surface growth and interfacial diffusion during Al deposition. Coating thickness, composition and phase profile results of both models were compared with experimental results, and most compatible model was determined. Using the model with best compatibility, effect of CVD operation time, temperature and deposition rate were investigated using DICTRA software. Main criteria were to create a pure and uniform β-NiAl zone with high Al content (35-55 %at.), and to maximize β-NiAl to interdiffusion zone thickness ratio to improve the lifetime and mechanical properties of IN 738 LC turbine blades. After the simulations were completed, results were compared with experimental CVD results and simulation model was modified to carry out more compatible results with real life CVD operations.
3rd International Conference OnThermophysical And MechanicalProperties OfAdvancedMaterials (THERMAM 2016), 1 –3 SEPTEMBER 2016

Suggestions

Production and development of aluminide coatings by chemical vapor deposition on nickel based superalloys for turbine engine applications
Ertürk, Umutcan; İmer, Muhsine Bilge; Department of Metallurgical and Materials Engineering (2017)
Diffusion coatings including aluminide coatings are utilized to improve the high temperature oxidation and corrosion resistance of turbine blades. Through the advancement in the aluminizing methods, higher purity and more homogeneously distributed coatings have been realized. The chemical vapor deposition (CVD) is the most advanced technique utilized for aluminizing process. The versatility of CVD provides a large possibility to control process variables such as temperature, pressure, gas flows and ratios, ...
Optimization of chemical vapor deposition process parameters for aluminizing
Ertürk, Umutcan; İmer, Muhsine Bilge (2016-08-01)
Ni-based super alloys such as Inconel 738LC, MAR-M-200, CMSX-4 are used in the hot sections of industrial gas turbines due to their excellent mechanical strength and creep resistance at high service temperatures. To protect turbine blades from thermo-mechanical failure, oxidation/corrosion resistant coatings are necessary to extend the life time. For this purpose, diffusion coatings including chromized, siliconized, aluminide coatings have been studied by different groups. Among them, aluminide coatings are...
Synthesizing Cation Doped Stable Alpha Nickel Hydroxide Having Low Self Discharge Rate By Chemical Precipitation
İlhan, Turan; Karakaya, İshak; Department of Metallurgical and Materials Engineering (2022-2-11)
Nickel hydroxide is one of the commonly used active material in batteries and supercapacitors. It has two phases which are α-Ni(OH)2 and β-Ni(OH)2. The alpha phase has higher electrochemical performances due to its higher oxidation state but it has poor stability, chargeability and self-discharge performances. Studies in both industry and academiy is focusing on to solve those problems. Effects of cation doping and starting precursor on those problems were investigated in this study. Materials were synthesi...
The effects of Cr addition on the atomic ordering properties of Ni based superalloys
Eriş, Rasim; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (null; 2016-10-01)
Nickel-based superalloys are used in turbine blades, nuclear reactors and power plants due to their excellent mechanical properties and oxidation-corrosion resistance at high temperatures. The superior properties of Nickelbased superalloys are further improved by alloying element additions which lead to formation of coherently GLVWULEXWHG RUGHUHG Ȗ¶ SUHFLSLWDWHV 1L3$O ZLWKLQ Ȗ 1L matrix. Enhancement of mechanical properties has been attributed to Al-sublattice site occupancy of tertiary DOOR\LQJHOHPHQWV...
The influence of flow forming on the precipitation characteristics of Al2024 alloys
Karakaş, Aptullah; Fenercioğlu, Tevfik Ozan; Yalçınkaya, Tuncay (2021-09-15)
Aluminum alloys are heat treated for better specific strength. In certain cases, an intermediate cold work is applied between solution heat treatment and aging. In this study, a specific tube forming technique called flow forming is applied as the intermediate cold work to produce Al2024-T8 grade tubes, resulting in enhancement of mechanical properties. The correlation between the amount of cold work and final mechanical properties is studied through tensile tests, SEM and XRD. The study is concluded with a...
Citation Formats
M. T. Boyraz and M. B. İmer, “Aluminide Coating Simulations,” presented at the 3rd International Conference OnThermophysical And MechanicalProperties OfAdvancedMaterials (THERMAM 2016), 1 –3 SEPTEMBER 2016, Izmir, Turkey, 2016, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/86166.