S. Babu

Bio: S. Babu is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Welding & Aluminium alloy. The author has an hindex of 19, co-authored 32 publications receiving 1049 citations. Previous affiliations of S. Babu include Annamalai University.

Optimizing friction stir welding parameters to maximize tensile strength of AA2219 aluminum alloy joints

Abstract: AA2219 aluminium alloy (Al-Cu-Mn alloy) has gathered wide acceptance in the fabrication of lightweight structures requiring a high strength-to-weight ratio and good corrosion resistance. In contrast to the fusion welding processes that are routinely used for joining structural aluminium alloys, the friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force etc., and the tool pin profile play a major role in determining the joint strength. An attempt has been made here to develop a mathematical model to predict the tensile strength of friction stir welded AA2219 aluminium alloy by incorporating FSW process parameters. A central composite design with four factors and five levels has been used to minimize the number of experimental conditions. The response surface method (RSM) has been used to develop the model. The developed mathematical model has been optimized using the Hooke and Jeeves search technique to maximize the tensile strength of the friction stir welded AA2219 aluminium alloy joints.

Use of Friction Surfacing for Additive Manufacturing

Abstract: In this work, we explore the possibility of utilizing friction surfacing, an emerging solid-state surface coating process, for layer-by-layer manufacture of three-dimensional metallic parts. One possibility in this regard (single-track friction surfacing) is to utilize friction surfacing for depositing a track or layer of material (sufficiently wide to cover the entire layer area), which is subsequently shaped to its corresponding slice counter using CNC machining. Another possibility (multi-track friction surfacing) is to generate a layer from multiple overlapping tracks of friction surfaced material, which is subsequently shaped as required using CNC machining. In the current work, sound multi-layered deposits in various ferrous materials were realized using friction surfacing in both single- and multi-track approaches. Samples with fully enclosed internal cavities and those consisting of different materials in different layers were also successfully produced. The deposits showed fine-grain wrought micr...

Application of Response Surface Methodolody to Prediction of Dilution in Plasma Transferred Arc Hardfacing of Stainless Steel on Carbon Steel

Abstract: The application of response surface methodology was highlighted to predict and optimize the percentage of dilution of iron-based hardfaced surface produced by the PTA (plasma transferred arc welding) process. The experiments were conducted based on five-factor five-level central composite rotatable design with full replication technique and a mathematical model was developed using response surface methodology. Furthermore, the response surface methodology was also used to optimize the process parameters that yielded the lowest percentage of dilution.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON