Search

In this study, the effect of machining parameters on Ra (average surface roughness), Rq (quadratic average roughness) and Rz (maximum roughness) values were measured on the material cut surface as a result of machining Inconel 718 (IN718) superalloy on a CNC wire erosion machine were investigated. As the processing parameters; voltage, wire feed rate and dielectric fluid pressure were determined. In the experiments, pure water was used as the dielectric fluid and 0.3 mm brass wire was used as the wire. The aim of the study is to determine the optimum values of the cutting parameters in order to obtain the lowest Ra, Rq and Rz values. Gray Relational Analysis (GRA), which is one of the multi-criteria decision-making methods, has been applied for the optimization of the machining parameters in the cutting process with the wire erosion machine. The experiments and the levels of the parameters used were designed and optimized according to the Taguchi L9 (33) orthogonal array. Analysis of Variance (ANOVA) was used to determine the effect percentages of the cut-off parameters. The parameter with the highest effect was determined as voltage with a ratio of 79.18% for Ra, 84.05% for Rq, and 89.25% for Rz. The lowest Ra, Rq and Rz values were obtained as 0.123 μm, 0.178 μm and 0.740 μm, respectively. [ABSTRACT FROM AUTHOR]

Fiber reinforced polymer (FRP) composite materials are heterogeneous and anisotropic materials that do not exhibit plastic deformation. They have been used in a wide range of contemporary applications particularly in space and aviation, automotive, maritime and manufacturing of sports equipment. Carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composite materials, among other fiber reinforced materials, have been increasingly replacing conventional materials with their excellent strength and low specific weight properties. Their manufacturability in varying combinations with customized strength properties, also their high fatigue, toughness and high temperature wear and oxidation resistance capabilities render these materials an excellent choice in engineering applications. In the present review study, a literature survey was conducted on the machinability properties and related approaches for CFRP and GFRP composite materials. As in the machining of all anisotropic and heterogeneous materials, failure mechanisms were also reported in the machining of CFRP and GFRP materials with both conventional and modern manufacturing methods and the results of these studies were obtained by use of variance analysis (ANOVA), artificial neural networks (ANN) model, fuzzy inference system (FIS), harmony search (HS) algorithm, genetic algorithm (GA), Taguchi's optimization technique, multi-criteria optimization, analytical modeling, stress analysis, finite elements method (FEM), data analysis, and linear regression technique. Failure mechanisms and surface quality is discussed with the help of optical and scanning electron microscopy, and profilometry. ANOVA, GA, FEM, etc. are used to analyze and generate predictive models. [ABSTRACT FROM AUTHOR]