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

The Design and Analysis of Experiments

The improvements of surface quality and dimensional accuracy are critical for Wire and Arc Additive Manufacturing (WAAM). This paper highlights a multi-objective optimization process for Bainite steel additive manufacturing. The welding design matrix for conducting the experiments was made by using the Box-Behnken design of response surface methodology (RSM). The input process parameters were varied at three levels which result in 46 experimental trials. The responses were measured during or after conducting the experiments. A second-order response surface model was developed and then multi-objective optimization was performed to obtain the desired surface appearance. The acceleration and staggered deposition processes were used to decrease the head dimension of single weld bead. The results show that the optimized sample surface appearance is smooth which has little spatters and no visible defects. Compared with the traditional processes which rely on overlapping rate adjustment but weaken the single weld bead morphology optimization, the process of this paper has comprehensive considerations of droplet transfer, heat input, and shaping coefficient. It enables the capacity of fabricating metal parts with high accuracy and lays a good foundation for Bainite steel additive manufacturing.

Optimization of surface appearance for wire and arc additive manufacturing of Bainite steel

of the simple linear regression model. Multiple linear regression for two variables is discussed in Chapter 8, and that for more than two variables is covered in Chapter 9. Chapter 10, on model building, is perhaps the book’s strongest chapter. The authors provide one of the most intuitive discussions on variable transformations that I have seen. Nice presentations of indicator variables, variable selection, and influence diagnostics are also provided. The final chapter covers a wide variety of topics, including analysis of variance models, logistic regression, and robust regression. The coverage of regression is not matrix-based, but optional linear algebra sections at the end of each chapter are useful for one wishing to use matrices. In general, the writing is clear and conceptual. A good number of exercises (about 20 on average) at the end of each chapter are provided. The exercises emphasize derivations and computations. It is difficult to name some comparison texts. Certainly, the text by Ott and Longnecker (2001) would be more suitable for a statistical methods course for an interdisciplinary audience. The regression texts of Montgomery, Peck, and Vining (2001) and Mendenhall and Sincich (2003) are more comprehensive in the regression treatment than the reviewed text. However, Introduction to Linear Models and Statistical Inference is not meant to compete with these texts—rather, its audience is primarily those taking a statistics course within a mathematics department.

Quality by Experimental Design

Laccase-Prussian blue film-graphene doped carbon paste modified electrode for carbamate pesticides quantification.

Manufacturing can be defined as the transformation of raw materials into desired products by various processes, such as machining, welding and coating. Today, laser and arc heat sources are largely used as the means for processing raw materials. The laser is one of the most widely used non-contact thermal energy sources in various processes, and the development of laser processes and devices for effective manufacturing is still ongoing. Arc heat sources are widely used in welding and coating processes. In particular, the types of welding processes using arc heat sources are very different depending on the materials used and the purpose of welding. In this paper, individual processes using laser and arc heat that have been reported over the past five years are reviewed, including machining, welding, sintering and coating. Then, hybrid processes that use laser and arc heat sources together are also reviewed. The final part of this review provides a summary and discusses future trends for individual and hybrid processes using laser and arc heat sources.

Laser and Arc Manufacturing Processes: A Review

Pulsed current micro plasma arc welding (MPAW) is one of the most widely used welding processes in sheet metal manufacturing industry. In any fusion arc welding process, the weld bead geometry plays an important role in determining the mechanical properties of the weld and hence quality of the weld. Moreover, the geometry of weld bead involves several simultaneously multiple quality characteristics such as front width, back width, front height and back height, which must be closely monitored, controlled and optimised. This paper presents the optimization of the pulsed current MPAW process by using the grey relational analysis considering the aforementioned quality characteristics. The specific targets are maximum front width and back width, minimum front height and back height. Experiments were performed under different welding conditions such as peak current, base current, pulse frequency and pulse width using Inconel 625 sheets of 0.25 mm thick. A response surface method (RSM)-based central composite design (CCD) experimental design is used to conduct experiments. Optimal welding parameters were determined by the grey relational grade obtained from the grey relational analysis. Optimal results have been verified through confirmation experiments.

Application of grey relational analysis for optimizing weld bead geometry parameters of pulsed current micro plasma arc welded inconel 625 sheets

Micro Plasma Arc Welding plays a vital role in attaining good weld quality in various engineering applications like bellows, diaphragms etc. The main objective of the present work is to use current pulsing technique while welding SS304L sheets. The paper focuses on studying the influence of various Micro Plasma Arc Welding process parameters like peak current, back current, pulse and pulse width on the weld quality characteristics like weld pool geometry, microstructure, grain size, hardness and tensile properties. The results reveals that the usage of pulsing current, grain refinement has taken place in weld fusion zone, because of which improvement in weld quality characteristics have been observed.

A Study on Weld Quality Characteristics of Pulsed Current Micro Plasma Arc Welding of SS304L Sheets

Abstract AISI 304L is an austenitic Chromium-Nickel stainless steel offering the optimum combination of corrosion resistance, strength, and ductility. These attributes make it a favorite for many mechanical switch components. The low carbon content reduces susceptibility to carbide precipitation during welding. In the present paper a thorough review on welding of AISI 304L austenitic Stainless Steel by various welding processes was made. From the review it is understood that AISI 304L austenitic Stainless Steel is the best material where there is a problem of intergranular corrosion. Also it is one of the best materials frequently used in manufacturing non heat treatable components.

A Review on Welding of AISI 304L Austenitic Stainless Steel

https://cyberleninka.org/article/n/1266045.pdf

Study on Weld Quality Characteristics of Micro Plasma Arc Welded Austenitic Stainless Steels

AISI 304L is an austenitic Chromium-Nickel stainless steel offering the optimum combination of corrosion resistance, strength and ductility. These attributes make it a favorite for many mechanical components. The paper focuses on developing mathematical models to predict grain size and hardness of pulsed current micro plasma arc welded AISI 304L joints. Four factors, five level, central composite rotatable design matrix is used to optimize the number of experiments. The mathematical models have been developed by Response Surface Method (RSM) and its adequacy is checked by Analysis of Variance (ANOVA) technique. By using the developed mathematical models, grain size and hardness of the weld joints can be predicted with 99% confidence level. The developed mathematical models have been optimized using Hooke and Jeeves algorithm to minimize grain size and maximize the hardness.

/pdf/application-of-hooke-jeeves-algorithm-in-optimizing-fusion-424htdsehm.pdf

Kondapalli Siva Prasad

Papers

Application of grey relational analysis for optimizing weld bead geometry parameters of pulsed current micro plasma arc welded inconel 625 sheets

A Study on Weld Quality Characteristics of Pulsed Current Micro Plasma Arc Welding of SS304L Sheets

A Review on Welding of AISI 304L Austenitic Stainless Steel

Study on Weld Quality Characteristics of Micro Plasma Arc Welded Austenitic Stainless Steels

Application of Hooke & Jeeves Algorithm in Optimizing Fusion Zone Grain Size and Hardness of Pulsed Current Micro Plasma Arc Welded AISI 304L Sheets