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

Additive manufacturing of metallic components – Process, structure and properties

Freedom of design, mass customisation, waste minimisation and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing (AM) or 3D printing. A comprehensive review of the main 3D printing methods, materials and their development in trending applications was carried out. In particular, the revolutionary applications of AM in biomedical, aerospace, buildings and protective structures were discussed. The current state of materials development, including metal alloys, polymer composites, ceramics and concrete, was presented. In addition, this paper discussed the main processing challenges with void formation, anisotropic behaviour, the limitation of computer design and layer-by-layer appearance. Overall, this paper gives an overview of 3D printing, including a survey on its benefits and drawbacks as a benchmark for future research and development.

Additive manufacturing (3D printing): A review of materials, methods, applications and challenges

This paper reviews the state-of-the-art of an important, rapidly emerging, manufacturing technology that is alternatively called additive manufacturing (AM), direct digital manufacturing, free form fabrication, or 3D printing, etc. A broad contextual overview of metallic AM is provided. AM has the potential to revolutionize the global parts manufacturing and logistics landscape. It enables distributed manufacturing and the productions of parts-on-demand while offering the potential to reduce cost, energy consumption, and carbon footprint. This paper explores the material science, processes, and business consideration associated with achieving these performance gains. It is concluded that a paradigm shift is required in order to fully exploit AM potential.

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Metal Additive Manufacturing: A Review

Recent advances in friction-stir welding : Process, weldment structure and properties

Modelling the friction stir welding of aerospace alloys

Residual Stress Reduction in High Pressure Interpass Rolled Wire+Arc Additive Manufacturing Ti-6Al-4V Components

One technique for reducing residual stress in welds is high pressure rolling of the weld seam. In this study, a variety of experimental techniques, including microhardness measurements and cross-weld tensile tests with digital image correlation, have been used to characterise the effects of rolling on the mechanical properties and microstructure of the weld material in welded structural steel specimens. It is shown that rolling applied at high temperature, as welding is carried out, promotes the formation of acicular ferrite in the weld metal. This produces a weld material with a greater yield strength and hardness, but slightly reduced impact toughness compared to unrolled welds. Rolling of the weld metal once it has cooled instead causes work-hardening. These effects are discussed as they relate to the use of rolling for weld residual stress reduction.

Paul A. Colegrove

Papers

Modelling the friction stir welding of aerospace alloys

Residual Stress Reduction in High Pressure Interpass Rolled Wire+Arc Additive Manufacturing Ti-6Al-4V Components

High-pressure rolling of low-carbon steel weld seams: Part 1 - Effects on mechanical properties and microstructure

A system approach for modelling additive manufacturing in defence acquisition programs

Thermal and microstructure modelling in thick plate aluminium alloy 7075 friction stir welds