Session: 03-08-02: Computational Modeling and Simulation for Advanced Manufacturing

Paper Number: 143537

143537 - Comparative Numerical Analysis of Tool Tilt Effects in Friction Stir Processing of Az91: Exploring Sph Applications 

Modern environmental regulations emphasize the importance of lighter vehicles to enhance fuel efficiency and reduce the automotive industry’s carbon footprint. One approach is to explore lightweight structural alloys, with magnesium being the lightest structural metal. It weighs approximately 1.7 times less than aluminium and about 4.5 times less than steel, making it slightly heavier than carbon fibre. This unique combination of lightweight properties and structural strength makes magnesium valuable for various industries, including automotive and aerospace, where reducing weight improves fuel efficiency, lowers emissions, and enhances overall performance. Magnesium alloys like AZ91 are chosen in industries for their excellent castability, heat dissipation, and high strength-to-weight ratio, meeting modern efficiency and environmental regulations. However, their Hexagonal Close-Packed (HCP) structure, with fewer slip systems than other crystal structures, can present challenges in deformation, resulting in reduced strength, ductility, and surface characteristics. Friction Stir Processing (FSP) is a novel technology that provides heat for deformation below the material’s melting point, overcoming limitations of conventional Severe Plastic Deformation (SPD) techniques. Key machine variables in FSP, including tool rotational speed (TRS), tool traverse speed (TTS), and tool tilt angle (TTA), are critical for heat generation, material softening, promoting material mixing, and achieving a seamless processed material. In experimental studies, improving properties depends on microstructural changes, material flow, and particle dispersion. However, a complete understanding of the complex, interconnected, non-linear physical phenomena in FSP cannot be achieved solely through experiments. Thus, insights from numerical analysis are crucial. Previous techniques such as Lagrangian, Eulerian, Arbitrary Lagrangian-Eulerian (ALE), and Coupled Eulerian-Lagrangian (CEL) had difficulties with transportable boundaries, particularly in intricate geometries, resulting in stability problems with dynamic grid meshes. Smoothed Particle Hydrodynamics (SPH) offers advantages over traditional grid-based methods with its mesh-free adaptable nature to complex geometries, dynamic interfaces, and material deformation. Fully exploring SPH’s potential to predict defects and analyzing temperature distribution with material flow with tool tilt variations in FSP of AZ91 is crucial. Altair RADIOSS Finite Element Method-based software is vital for simulating real-world scenarios, offering advanced capabilities in handling large deformations and complex interactions. Its accurate predictions under dynamic loads have improved product performance and reduced development costs. Thus, the current study compares two cases, one with tool tilt and one without, using constant TRS and TTS while varying TTA to understand the impact of tool tilt on temperature and material flow using the mesh-free approach with Altair RADIOSS. It was observed that the temperatures obtained with the tool tilt are higher than those without tool tilt. The percentage difference between both models is comparable, and both validated numerical models show overall performance criteria within an acceptable range. Material flow was also predicted and compared within the models, clearly showing. Integrating SPH with experimental data can potentially improve the cost-effectiveness of designing FSP experiments on AZ91.

Presenting Author: Srinivasa Rao Pedapati The University of Texas Permian Basin

Presenting Author Biography: Srinivasa Rao Pedapati is an active researcher with 30+ years of teaching & research experience. Dr. Pedapati working as a faculty of Mechanical Engineering in The university of Texas Permian Basin since August 2023.He has published 105 articles in refereed journals and successfully supervised diverse learners from India, Malaysia, Pakistan, and the Middle East for their doctoral degrees (PhD). Dr. Pedapati completed 8 research projects funded by Industry and Government agencies in Malaysia and India, amounting to a total of $500,000.His research interests are Welding, Friction Stir Welding, Friction stir processed composites, Artificial Intelligence applications, and O&G pipelines.

Authors:

Roshan Vijay Marode Universiti Teknologi PETRONAS
Tamiru Alemu Lemma Universiti Teknologi PETRONAS
Srinivasa Rao Pedapati The University of Texas Permian Basin
Nabihah Sallih Universiti Teknologi PETRONAS
Mokhtar Awang Universiti Teknologi PETRONAS
Adeel Hassan Universiti Teknologi PETRONAS