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

Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting....

Polymers for 3D Printing and Customized Additive Manufacturing

The use of 3D printing for rapid tooling and manufacturing has promised to produce components with complex geometries according to computer designs. Due to the intrinsically limited mechanical properties and functionalities of printed pure polymer parts, there is a critical need to develop printable polymer composites with high performance. 3D printing offers many advantages in the fabrication of composites, including high precision, cost effective and customized geometry. This article gives an overview on 3D printing techniques of polymer composite materials and the properties and performance of 3D printed composite parts as well as their potential applications in the fields of biomedical, electronics and aerospace engineering. Common 3D printing techniques such as fused deposition modeling, selective laser sintering, inkjet 3D printing, stereolithography, and 3D plotting are introduced. The formation methodology and the performance of particle-, fiber- and nanomaterial-reinforced polymer composites are emphasized. Finally, important limitations are identified to motivate the future research of 3D printing.

3D printing of polymer matrix composites: A review and prospective

A Pallet Loading Problem (PLP) occurs when identical rectangular boxes are to be stacked and packed on a rectangular pallet. The problem has many practical applications in distribution and logistics in packaging industries. An increase in the number of boxes that can be shipped on a pallet directly reduces the cost. In automated manufacturing palletising operations, the Pallet Loading Problem (PLP) usually deals with generating optimal pallet patterns of boxes on a pallet but a purely mathematical solution does not consider the physical aspects and restrictions encountered when using the robot and the gripper to implement these patterns. Therefore, merely getting an optimal pallet pattern does not guarantee an optimal pattern placement strategy. Very few published literature is available to address this problem, there is a need to develop a methodology that considers the palletisers physical characteristics and limitations in robotic palletising systems. This paper presents the development of a pallet pattern placement strategy with practical implementations for five-block patterns with the aim of improving the operational efficiency in robotic palletisation.

An investigation on the operational improvement in robotic palletisation

This paper presents an investigation on the microstructure and surface hardness of the parts fabricated by laser assisted Direct Metal Deposition (DMD) technology. A series of engineering metallic alloy powders were used in the DMD process to produce simple 3D geometric structures. The alloy powders investigated include: 316L stainless steel, 420 Stainless Steel, Stellite(R) 6, tool steel (H13), Cholmoloy (Ni Based alloy), and Aluminium Bronze. These were chosen due to their frequent application in engineering parts and components. The microstructure and hardness values have been compared to those of the wrought products (as annealed) as reported in the SAE standards, Heat treater’s guide to metals ASM international, and material data sheets supplied by the materials manufacturers. A significant difference is reported in both hardness and microstructure of the laser deposited samples compared to those of the wrought form.

A study of microstructure and surface hardness of parts fabricated by laser direct metal deposition process

Design of a 3D-printable UHF RFID hybrid liquid antenna for biosensing applications

In High Pressure Die Casting (HDPC) process, chill vents are used to allow residual air and gases to exhaust out from the mould cavity. The objective of this paper is to design and develop a high-performance chill vent for high pressure die casting using a new type of copper alloy material, which has high strength and high thermal conductivity, compared to conventional tool steel. Finite element analysis is applied to develop a numerical heat transfer model for chill vent and validated by experimental results. The model is used to compare the performance of copper alloy chill vent with conventional steel chill vent. It was found that the change in the chill vent material had a significant improvement on the cooling time, cooling rate as well as on the internal die temperature distribution. Results show that the copper chill vent increases the cooling efficiency of the solidifying aluminium alloy by about 158% compared to the conventional steel chill vents. It is concluded that the use of high strength copper alloy chill vents will enhance the efficiency and effectiveness of HPDC process with rapid heat transfer and faster release of gases, thus reducing porosity and flashing defects in the parts. 

/pdf/development-of-high-performance-copper-alloy-chill-vent-for-1vvjev3l1y.pdf

Syed H. Masood

Papers

An investigation on the operational improvement in robotic palletisation

A study of microstructure and surface hardness of parts fabricated by laser direct metal deposition process

Design of a 3D-printable UHF RFID hybrid liquid antenna for biosensing applications

Development of High Performance Copper Alloy Chill Vent for High Pressure Die Casting

Evaluation of CNC and SLA as prototyping techniques