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

Determining the effect of cutting parameters on surface roughness in hard turning using the Taguchi method

Purpose – Ti‐6Al‐4V is one of the most attractive materials being used in aerospace, automotive and medical implant industries. Electron beam melting (EBM) is one of the direct digital manufacturing methods to produce complex geometries of fully dense and near net shape parts. The EBM system provides an opportunity to built metallic objects with different processing parameter settings like beam current, scan speed, probe size on powder, etc. The purpose of this paper is to determine and understand the effect of part's thickness and variation in process parameter settings of the EBM system on surface roughness/topography of EBM fabricated Ti‐6Al‐4V metallic parts.Design/methodology/approach – A mathematical model based upon response surface methodology (RSM) is developed to study the variation of surface roughness with changing process parameter settings. Surface roughness of the test slabs produced with different parameter settings and thickness has been studied under confocal microscope. Response surface...

Effect of process parameters settings and thickness on surface roughness of EBM produced Ti‐6Al‐4V

Developments in polyester composite materials – An in-depth review on natural fibres and nano fillers

This paper offers a comprehensive literature review of the conventional machining processes along with optimization methods used in metal matrix composites (MMCs), such as turning, milling, drilling, and grinding machining processes. The tool wear mechanism and machinability of MMCs along with surface quality are discussed in the number of different manufacturing processes and examined thoroughly. Additionally, the manufacturing of MMC products through nonconventional machining processes such as electrical discharge machining (EDM), wire electrical discharge machining (WEDM), laser machining, electrochemical machining, ultra- sonic machining (USM), and high-speed machining are investigated and considered, in connection with MMC processing are discussed, as alternatives to the aforementioned processes. Moreover, this review focuses on the modeling of the machining process, finite element modeling, and simulation and optimization of soft computing methods in MMCs. The study will emphasize on the most generally used methods, namely, response surface methodology, artificial neural network, Taguchi method, and fuzzy logic as soft computing optimization methods. Finally, the comprehensive open issues and conclusions have drawn on the machining and optimization of particle-reinforced MMCs.

A review on machining and optimization of particle-reinforced metal matrix composites

This paper presents the study on Taguchi's optimization methodology, which is applied to optimize cutting parameters in turning of age hardened Al6061-15% vol. SiC 25 µm particle size metal matrix composites with Cubic boron nitride inserts (CBN) KB-90 grade using steam as cutting fluid. Analysis of variance (ANOVA) is used to study the effect of process parameters on the machining process. This procedure eliminates the need for repeated experiments, time and conserves the material by the conventional procedure. The turning parameters evaluated are speed, feed, depth of cut, nozzle diameter and steam pressure. A series of experiments are conducted using PSG A141 lathe (2.2 KW) to relate the cutting parameters on surface roughness, tool wear, cutting force, feed force, and thrust force. The measured results were collected and analyzed with the help of the commercial software package MINITAB15. As well, an orthogonal array, signal-to-noise ratio is employed to analyze the influence of these parameters. The method could be useful in predicting surface roughness, tool wear, cutting force, feed force and thrust force as a function of cutting parameters. From the analysis using Taguchi's method, results indicate that among the all-significant parameters, steam pressure is the most significant parameter.

http://www.scielo.br/pdf/jbsmse/v31n1/v31n1a03.pdf

Taguchi's technique in machining of metal matrix composites

In this paper, the effects and the optimization of machining parameters on surface roughness in the grinding of 6061Al-SiC25P (MMCs) specimen are investigated. In the grinding process, a machining parameter, such as hardness of the specimen, flow rate of the coolant and depth of cut while machining were chosen for evaluation by the response surface methodology. By response surface methodology, a complete realization of the process parameters and their effects were achieved. The variation of surface roughness with machining parameters was mathematically modeled using response surface methodology. Finally, experimentation was carried out to identify the effectiveness of the proposed method.

APPLICATION OF RESPONSE SURFACE METHODOLOGY ON SURFACE ROUGHNESS IN GRINDING OF AEROSPACE MATERIALS (6061Al-15Vol%SiC25P)

Due to the advancement in the field of biocomposites, the role of plant fiber-reinforced composites has increased over the last few years. Now, these materials are used for both serviceable and non-serviceable applications. The components to be manufactured by natural fiber-reinforced composites can be created using simple manufacturing techniques. However, joining of these manufactured parts has been the major difficulty faced by manufacturers. Extensive research has been carried out in drilling of polymer matrix composites and metal matrix composites, however, the studies on the behavior of natural fiber reinforced composites are limited. Hence an attempt has been made to study the mechanical characterization, machinability and microstructural study of Discontinuously Reinforced Sisal Fiber Polyester (DRSFP) composite laminates. From the experimental results it is observed that Moisture absorption was 1.4% for 40 hours' time period due to porosity content, the lumen and fiber-matrix adhesion, at higher load frictional thrust increases and resulted in increased debonding and fracture, main effects plot for three body abrasive wear indicates the selection of less Load (4kg) and less speed (100 rpm) results in the best combination to get minimum abrasive wear value, selection of Spindle speed (1500 rpm), Feed rate (10 mm/min) and Point angle (90°) resulted in the best combination to get better surface roughness and minimum delamination. From the SEM micrographs of the drilled hole of DRSFP composites, it is observed that the hole drilled at point angle 118° has severely damaged surface compared to point angle 90° and 104° due to more fiber pull-out, surface and subsurface cracks (radial direction), de-bonding of fiber-matrix.

Mechanical and machinability study on discontinuously reinforced sisal fibre polyester composite laminates

Pressure vessels are widely used in industries for processing and storing fluids which are at different temperature and pressure in analogous to ambient. The design of these pressure vessels become the most paramount factor as any discrepancy would cause the vessel to explode, leading to injure many humans and failure of the setup. This paper designs the pressure vessel according to the pressure vessel handbook for both hemispherical and flat dish end pressure vessel so as to determine the most economic and efficient design. The various stresses engendered within the vessel were calculated and were learned to be within the permissible limits. The outer and inner diameter of the vessel was found to be 607mm and 480mm and the thickness of the vessel was determined to be 63.5mm. This design could withstand an internal pressure and temperature of 150psi and 500°F. The dimensions obtained from the design were further used to model both hemispherical and flat dish end pressure vessel with help of CAD in Catia V5R19.

Design and Modelling of Hemispherical and Flat Dish End Pressure Vessel

Most products based on elastomers are produced by some kind of molding and curing process. This paper deals with a new method of elastomer machining. A series of cutting experiments under different rake angle, cutting speed, feed and constant depth of cut has been conducted on cutting force and surface roughness under ambient and cryogenic condition. From experimental data it can be clearly seen that increase of cutting force become more significant with higher cutting speeds for cryogenic cutting. Cryogenic machining showed remarkable reduction in surface roughness compared ambient machining especially at high rake angle.

Rajesh Nayak

Papers

Taguchi's technique in machining of metal matrix composites

APPLICATION OF RESPONSE SURFACE METHODOLOGY ON SURFACE ROUGHNESS IN GRINDING OF AEROSPACE MATERIALS (6061Al-15Vol%SiC25P)

Mechanical and machinability study on discontinuously reinforced sisal fibre polyester composite laminates

Design and Modelling of Hemispherical and Flat Dish End Pressure Vessel

Cutting force and surface roughness in cryogenic nachining of elastomer