Browsing by Author "Dhulipalla, Anvesh"

Now showing 1 - 4 of 4
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    Finite Element Modeling of Coating Thickness Using Heat Transfer Method
    (Elsevier, 2021-01) Li, Yafeng; Dhulipalla, Anvesh; Zhang, Jian; Park, Hye-Yeong; Jung, Yeon-Gil; Koo, Dan Daehyun; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and Technology
    A new heat transfer based finite element model is proposed to simulate coating thickness in the electron-beam physical vapor deposition (EB-PVD) process. The major advantage of the proposed model is that it is much computationally efficient than the traditional ray-tracing based model by about two orders of magnitude. This is because the Gaussian distribution heating source has the same profile as the cosine relation used in the ray-tracing method. Firstly, the model simulates the temperature profile of a metal substrate heated by a heating source with a Gaussian distribution. Then using a calibrated conversion process, the temperature profile is converted to corresponding coating thickness. The model is successfully demonstrated by three validation cases, including a stationary disk, a stationary cylinder, and a rotary three-pin component. The predicted coating thicknesses in the validation cases are in good agreement with either the ray-tracing based analytical solution or experimental data. After its validation, the model is applied to a rotary turbine blade to predict its coating thickness distribution. In summary, the model is capable to simulate coating thickness in complex shaped parts.
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    Synthesis and machining characteristics of novel TiC ceramic and MoS2 soft particulate reinforced aluminium alloy 7075 matrix composites
    (Elsevier, 2020-04) Dhulipalla, Anvesh; Kumar, Budireddy Uday; Akhil, Varupala; Zhang, Jian; Lu, Zhe; Park, Hye-Yeong; Jung, Yeon-Gil; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and Technology
    In this work, the synthesis and machinability studies are presented for a new TiC ceramic and MoS2 soft particulate reinforced aluminium alloy 7075 (AA7075) matrix composite (AMCs). The results show that the AMCs have improved machinability compared with the base AA7075. The chip morphology is changed from continuous sheared chips in AA7075 to discontinuous chips in AMCs. The change is caused by the reduced ductility in AMCs due to reinforcement TiC and MoS2 microparticles. The surface roughness is increased for the AMCs when compared to that of base alloy due to hard TiC particles.
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    Thickness Prediction of Deposited Thermal Barrier Coatings using Ray Tracing and Heat Transfer Methods
    (2020-12) Dhulipalla, Anvesh; Zhang, Jing; Yang, Shengfeng; Agarwal, Mangilal
    Thermal barrier coatings (TBCs) have been extensively employed as thermal protection in hot sections of gas turbines in aerospace and power generation applications. However, the fabrication of TBCs still needs to improve for better coating quality, such as achieving coating thickness' uniformity. However, several previous studies on the coating thickness prediction and a systematic understanding of the thickness evolution during the deposition process are still missing. This study aims to develop high-fidelity computational models to predict the coating thickness on complex-shaped components. In this work, two types of models, i.e., ray-tracing based and heat transfer based, are developed. For the ray-tracing model, assuming a line-of-sight coating process and considering the shadow effect, validation studies of coating thickness predictions on different shapes, including plate, disc, cylinder, and three-pin components. For the heat transfer model, a heat source following the Gaussian distribution is applied. It has the analogy of the governing equations of the ray-tracing method, thus generating a temperature distribution similar to the ray intensity distribution in the ray-tracing method, with the advantages of high computational efficiency. Then, using a calibrated conversion process, the ray intensity or the temperature profile are converted to the corresponding coating thickness. After validation studies, both models are applied to simulate the coating thickness in a rotary turbine blade. The results show that the simulated validation cases are in good agreement with either the experimental, analytical, or modeling results in the literature. The turbine blade case shows the coating thickness distributions based on rotating speed and deposition time. In summary, the models can simulate the coating thickness in rotary complex-shaped parts, which can be used to design and optimize the coating deposition process.
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    Three-dimensional analytical models for predicting coating thickness on non-axial symmetrical workpieces in electron beam physical vapor deposition
    (Elsevier, 2022-08) Li, Yafeng; Ji, Zhengzhao; Dhulipalla, Anvesh; Zhang, Jian; Yang, Xuehui; Dube, Tejesh; Kim, Bong-Gu; Jung, Yeon-Gil; Koo, Dan Daehyun; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and Technology
    In this work, three-dimensional (3D) analytical models for non-axial symmetric workpieces, including ellipsoid and cylinder, are derived to predict the coating thickness distributions in the EB-PVD process. Additionally, 3D analytical models for axial symmetric workpieces, including disk and sphere are presented, which will be used for deriving the non-axial symmetric workpiece solutions. The models are based on extending the two-dimensional (2D) models of a disk workpiece by Schiller et al. (1982) and a circular arc on a cylinder by Fuke et al. (2005). The 3D models for disk and sphere workpieces are also presented which are used to derive the non-axial symmetric models. The results show that the 3D analytical models are consistent with the 2D models, and also in excellent agreement with our finite element (FE) model predictions and experimental data in the literature.