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

A review on the production of metal matrix composites through stir casting – Furnace design, properties, challenges, and research opportunities

A review on the susceptor assisted microwave processing of materials

Electromagnetic stir casting is one of the simplest ways of producing defect free aluminum matrix composites. This work focuses on the fabrication of aluminum matrix composites reinforced with various weight percentages of SiC particulates and Fly-ash by modified electromagnetic stir casting route. The distribution of SiC and Fly-ash particles in the matrix was improved by providing externally argon gas into the melt during electromagnetic stirring. Five samples of hybrid composite with different combination of Fly-ash and SiC (25 μm) were prepared by electromagnetic stir casting method. Mechanical properties (tensile strength, hardness, toughness and fatigue strength) and microstructure of all five samples were analyzed. Microstructure presents that the reinforcements (SiC particulates and Fly-ash) are uniformly distributed in the matrix (A356). The results reveal that sample of A356/15 %SiC/5 % Fly-ash shows best result among all the selected samples. Density, porosity, specific strength and thermal expansion were also calculated to see the effect of Fly-ash addition.

Microstructure and mechanical behavior of A356/SiC/Fly-ash hybrid composites produced by electromagnetic stir casting

Summary form only given. We have investigated sintering, both with and without a plasma, reaction bonding of silicon nitride (RBSN), and chemical vapor infiltration (CVI) synthesis of ceramic matrix composites using microwave heating. The sintering rate of alumina in a plasma excited either by microwaves or induction coupling (5 MHz) is significantly greater than with conventional heating. The enhancement is believed to be caused by the creation of excess point defects by the plasma. Both microwave CVI and RBSN seek to take advantage of the temperature gradients inherent in volumetric heating so the reaction or deposition of matrix can take place from the center to the surface, thus enabling a greater degree of reaction than can be obtained by isothermal processing. Experimental and modeling results of these two processes are presented.

Microwave processing of ceramics

In the present investigation, A356 alloy 5 wt% SiC composite is fabricated by electromagnetic stir casting process. An attempt has been made to investigate the effect of CNC lathe process parameters like cutting speed, depth of cut, and feed rate on surface roughness during machining of A356 alloy 5 wt% SiC particulate metal-matrix composites in dry condition. Response surface methodology (Box Behnken Method) is chosen to design the experiments. The results reveal that cutting speed increases surface roughness decreases, whereas depth of cut and feed increase surface roughness increase. Optimum values of speed (190 m/min), feed (0.14 mm/rev) and depth of cut (0.20 mm) during turning of A356 alloy 5 wt% SiC composites to minimize the surface roughness (3.15μm) have been find out. The mechanical properties of A356 alloy 5 wt% SiC were also analyzed.

Effect of turning parameters on surface roughness of A356/5% SiC composite produced by electromagnetic stir casting

The friction stir welding is a pioneering solid-state metal joining technique for producing high-quality joints in materials. In this article, Taguchi approach is applied to analyze the optimal process parameters for optimum tensile strength and hardness of welded dissimilar A6061 and A6082 alloys. An orthogonal array of L9 is implemented and the analysis of variance is employed to investigate the importance of parameters on responses. The experimental tests, conducted according to combination of rotational speed, tool tilt and types of tool pin profile parameters. The results indicate that the rotational speed is most significant process parameter that has the highest influence on tensile strength and hardness, followed by tool pin profile and tool tilt. The optimum results verified by conducting confirmation experiments. The predicted optimal value of tensile strength and hardness of dissimilar joints produced by friction stir welding are 267.74 MPa and 80.55 HRB, respectively.

Optimization of process parameters for friction stir welding of joining A6061 and A6082 alloys by Taguchi method

Microwave welding process is almost in the league of joining the composite materials. But, it is really challenging to align with metals because they reflect the microwaves. In this paper, mild steel and stainless steel have been joined by the microwave welding at 2.45 GHz and 900 W. The joint has been formed at 600 sec exposure time. Ni-based powder is used to join the metals. The characterizations of joint have been carried out through microstructural analysis, tensile strength, elongation, and microhardness. The results reveal that the joint formation is clearly visible in microstructure. Tensile strength, elongation, and microhardness are 340.16 MPa, 11.67%, and 130 Hv, respectively.

Ajay Kumar

Papers

Effect of turning parameters on surface roughness of A356/5% SiC composite produced by electromagnetic stir casting

Optimization of process parameters for friction stir welding of joining A6061 and A6082 alloys by Taguchi method

Study of Joint Formed by Tungsten Carbide Bearing Alloy through Microwave Welding

Wear behaviour of friction stir weld joint of cast Al (4–10%) Cu alloy welded at different operating parameters

Characterization of A356/B4C composite fabricated by electromagnetic stir-casting process with vacuum