ملخص البحث :

In this paper, Response Surface Method (RSM) is utilized to carry out an investigation of the impact of input parameters: electrode type (E.T.) [Gr, Cu and CuW], pulse duration of current (Ip), pulse duration on time (Ton), and pulse duration off time (Toff) on the surface finish in EDM operation. To approximate and concentrate the suggested second- order regression model is generally accepted for Surface Roughness Ra, a Central Composite Design (CCD) is utilized for evaluating the model constant coefficients of the input parameters on Surface Roughness (Ra). Examinations were performed on AISI D2 tool steel. The important coefficients are gotten by achieving successfully an Analysis of Variance (ANOVA) at the 5 % confidence interval. The outcomes discover that Surface Roughness (Ra) is much more impacted by E.T., Ton, Toff, Ip and little of their interactions action or influence. To predict the average Surface Roughness (Ra), a mathematical regression model was developed. Furthermore, for saving in time, the created model could be utilized for the choice of the high levels in the EDM procedure. The model adequacy was extremely agreeable as the constant Coefficient of Determination (R2) is observed to be 99.72% and adjusted R 2 -measurement (R2 adj) 99.60%. Keywords: Response Surface Methodology, Electrical Discharge Machining, Central Composite Design, Analysis of Variance, Surface Roughness

ملخص البحث :

Electrochemical machining (ECM) is one of nontraditional processes, in many applications; it display many advantages including better precision, higher operating rate, control, no tool wear and machining a wide range of materials. Metal matrix composites (MMCs) have been increasingly used in industries, aerospace, and automobiles due to their superior properties compared to other alloys and that is due to the tough and abrasive hard reinforced particles. It’s complicated to machine materials by traditional processes methods the present study focused on the effect of electrolyte concentration, voltage, and Inter-electrode gap on radial over cut (ROC) and material removal rate (MRR) in electrochemical drilling of Al-5%SiC metal matrix composites. Based on Taguchi design the process parameters are optimized. Multiple Regression Model (MRM) was employed as model for radial over cut and material removal rate. The mathematical model was examined using analysis of variance (ANOVA).

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Ti/TiAlN coatings were deposited on tungsten carbide substrates and consist of the target Ti0.5Al0.5 using sputtering system is one of the main techniques which done be coating substrate. This research aimed is to develop the model a PVD magnetron sputtering process that can predict the relationship between process input parameters and the resulting coating properties and performance. RSM Response Surface Methodology was used, one of the most cost-effective and practical techniques to develop the process model. The influence of substrate thickness on the structural properties of the coatings was investigated and the effect of bias voltage on the microstructure was investigated. The number of crystallite grain size reduced with the increase of the bias voltage then reduce minimum roughness 0.07157 (µm) and became maximum roughness 0.7856 (µm). The crystalline grain size of the coatings increased as the bias voltage was raised from 50 to 75 V, and then decreased with further increase of the bias voltage.

ملخص البحث :

Magnetic Abrasive Finishing (MAF) process which is a non-traditional polishing technique, is suitable for variety of engineering materials, producing high quality surfaces of parts. An experimental setup study is made to carry out MAF process to improve surface layer quality and hardness of stainless steel grade 321 plate. This study uses two different magnetic pole shapes such as conical magnetic pole without grooves and conical magnetic pole with six grooves. The finally results show that the conical magnetic pole with six grooves can create best surface layer quality and improve hardness in (MAF) process. The process parameters are the applied number of pitches between grooves, finishing time, cutting speed of magnetic pole, voltage, and volume of powder (dose). The magnetic abrasive powder consisted of silicon carbide SiC, particle size 300μm, SiC (65%), it is mixed with the ferromagnetic iron particles (iron powders), particle size 300μm, Fe (35%). Taguchi matrix L18 for five input parameters with mixed level design (2-3) levels was used for designing the experiments and optimal values evaluation for all parameters to improve the hardness. By using MINITAB software data was analyzed, the results indicate that empirical equation (mathematical predicted models) represents the relation of the input parameters with the change in micro Vickers Hardness. The most significant parameters on change in hardness are volume of powder (42.34%) and number of pitches between grooves (25.30%). Keywords: magnetic abrasive finishing MAF parameters, micro Vickers hardness, MINITAB software, Taguchi matrix, Conical magnetic pole, Stainless steel.

ملخص البحث :

The production process of a triangle cup is very difficult method, due to the occurrence violent deformations at a narrow places of the forming region, as a result of non-uniform distribution of hoop compressive stresses and radial tensile stresses, so expected a lot of problems which accompany the forming. The most important is the surplus metal that composed at cup corners, because of the non-homogeneous flow of metals during entry into the die, so appear ears at the upper edge of the cup. To reduce that defect as little as possible, simulation model has been built by program (ANSYS 15) of deep drawing, and modify the blank from circular shape to triangular shape with a gradient corner radii (20, 28, and 35)mm. It was placed at opposite place to the draw tool form. The effect of the blank form on the required drawn force, distribution of thickness and strains that associated with the forming process were also studied. To make comparison between the experimental results and the results of simulation, it was manufacturing drawing tool with the same specifications of the simulation model. The practical and simulation results showed that the low radii corners of triangular blank lead to failure of deep drawing, especially at radii corners (20 and 28)mm. While the best shape of the cup by used blank with corner radius 35mm, that required less force of drawing, and better distribution of the metal thickness and the strains.

ملخص البحث :

Magnetic abrasive finishing (MAF) process is one of non-traditional or advanced finishing methods which is suitable for different materials and produces high quality level of surface finish where it uses magnetic force as a machining pressure. A set of experimental tests was planned according to Taguchi orthogonal array (OA) L27 (39) with three levels and six input parameters. Experimental estimation and optimization of input parameters for MA process for stainless steel type 316 plate work piece, six input parameters including amplitude of tooth pole, and number of cycle between teeth, current, cutting speed, working gap, and finishing time, were performed by design of experiment (DOE) and response surface methodology (R$M). These six input parameters in this research were optimized for all input parameters to improve the surface layer for work piece by using signal-to-noise ratio technique. The obtained results showed that all six input parameters have an influence on the change in surface roughness(ARa). In addition, the results showed that the surface roughness of the work piece decreased from 1.130 to 0.370m that means high level of improvement in the change of surface roughness (0.760)m.

ملخص البحث :

The effect of Magnetic Abrasive Finishing (MAF) method on the Temperature rise (Tr) and the surface Roughness (Ra) has been investigated in this research by determining the optimum temperature through the optimum surface roughness to improve the quality of surface layer for CuZn28 brass alloy plates. Sixteen runs were done in order to determine the optimum temperature in the contact area (between the abrasive powder and surface of workpiece) and the change in the surface Roughness (ARa) according to Taguchi Orthogonal Array (OA). Four technological parameters (cutting speed, finishing time, working gap and the current in the inductor) with four levels for each parameter have been used, the matrix known as a L16 (4’) OA. The Signal to Noise (S/N) ratio and Analysis of Variance (ANOVA) techniques were performed for analys ing results of Tr and ARa using the statistical software (MINITAB1 ), to establish the best optimum condition and identify the significant parameters affecting on the temperature rise and surface roughness. The modern and powerful technique IR camera was used to measure the temperature while scanning electron microscopy was utilized to study the texture of finishing surface. The results showed that the optimum temperature in contact area of workpiece is (55.1°C) and the most significant factor for CuZn28 brass effect on ARa for MAF process was the cutting speed followed by current in the inductor, finishing time and working gap.