Erol Kilickap

Selection of Optimum Drilling Parameters on Burr Height Using Response Surface Methodology and Genetic Algorithm in Drilling of AISI 304 Stainless Steel

This article illustrates an application of response surface methodology (RSM) and genetic algorithm (GA) for selecting the optimum combination values of drilling parameters affecting the burr height in drilling of AISI 304 stainless steel. The purpose of this article is to investigate the influence of the cutting parameters, such as cutting speed and feed rate, and point angle on burr height produced when drilling AISI 304 stainless steel. The experiments were conducted based on the Box–Behnken design. The measured results were collected and analyzed with the aid of a commercial software package Design Expert 6 and Matlab. A mathematical prediction model was developed using RSM) for the burr height. The effects of drilling parameters on the burr height were evaluated using RSM and optimum drilling conditions for minimizing the burr height were determined using GA. The GA optimization results have revealed that the minimum burr height was obtained at lower cutting speed and feed rates while at higher point angle.

Analysis and modeling of delamination factor in drilling glass fiber reinforced plastic using response surface methodology

This study, through a new approach, presents a comprehensive mathematical model for correlating the interactive and higher order influences of drilling parameters on the delamination factor in drilling glass fiber reinforced plastic (GFRP) composites using response surface methodology. The purpose of this article is to investigate the influence of drilling parameters, such as cutting speed, feed, and point angle on delamination produced when drilling GFRP composite. The damage generated associated with drilling GFRP composites were observed, both at the entrance and exit during the drilling. The experiments are conducted based on Box—Behnken design. Empirical models are developed to correlate and predict the drilling parameters and delamination factor in drilling of GFRP. The developed models for delamination factor at entrance and exit are proposed that agree well with the experiment. The models can be utilized to select the level of drilling parameters. Thus time and cost were noticeably reduced.

Empirical study regarding the effects of minimum quantity lubricant utilization on performance characteristics in the drilling of Al 7075

Cutting fluids are difficult and expensive to recycle. These drawbacks mentioned can be reduced or eliminated by performing the cutting operations with minimum quantity lubrication or without using any cutting fluid. In this study, the effects of different cutting parameters on performance characteristics are studied empirically during the drilling of Al7075. The work piece surface roughness and the temperature changes due to the incurred heat at the cutting process are taken as performance outputs. In the experiments, HSS tools with a diameter of 8 mm and an angle of 118o were used. Minimum quantity lubrication (MQL), compressed air and dry processing (without the usage of any cooling liquid) techniques are used as the applied cooling technique. In the processing technique with MQL, the cooling liquid is sent pulverized on the interface between the work piece and the tool. Boron oil-water emulsion is used as the cutting liquid. As a result of the experiments, it is determined that better results are achieved with the MQL technique than with other cooling techniques. The best surface roughness is achieved at 20 m/min cutting speed and 0.1 mm/rev feed rate.

Investigation of experimental study of end milling of CFRP composite

Abstract Carbon fiber-reinforced plastic (CFRP) composites are materials that are difficult to machine due to the anisotropic and heterogeneous properties of the material and poor surface quality, which can be seen during the machining process. The machining of these materials causes delamination and surface roughness owing to excessive cutting forces. This causes the material not to be used. The reduction of damage and surface roughness is an important aspect for product quality. Therefore, the experimental study carried out on milling of CFRP composite material is of great importance. End milling tests were performed at CNC milling vertical machining center. In the experiments, parameters considered for the end milling of CFRP were cutting speed, feed rate, and flute number of end mill. The results showed that damage, surface roughness, and cutting forces were affected by cutting parameters and flute number of end mill. The best machining conditions were achieved at low feed rate and four-flute end mill.

Effects of Cutting Parameters and Point Angle on Thrust Force and Delamination in Drilling of CFRP

Abstract Parts made of composite materials are generally produced by near-net-shape technology. However, additional machining operations such as drilling are often required to facilitate components assembling. Drilling of composite materials is also a common process in the assembly of aerospace and automotive composite structures. During drilling, unlike the conventional materials, a few damage forms may take place. Among these damage forms, the delamination is the most important one. Therefore, the experimental studies carried out on drilling of CFRP composite materials for determining optimum processing parameters are of great importance. In this particular study, delamination in CFRP composites caused by drilling was investigated. The composite material was drilled under various spindle speeds, feed rates and drill point angles. The results showed that delamination and thrust forces were affected by cutting parameters. It was demonstrated that feed rate and drill point angle make the largest contribution to the overall performance.

Optimisation of surface roughness with GA approach in turning 15% SiCp reinforced AlSi7Mg2 MMC material

In this study, 15% SiCP reinforced Metal Matrix Composite (MMC) AlSi7Mg2 material was turned by an uncoated WC cutting tool (K10) at cutting speeds of 50, 100 and 150 m/min, feed rates of 0.1, 0.2 and 0.3 mm/rev and depths of cut of 0.5, 1 and 1.5 and surface roughness values have been examined after each workpiece machined. A mathematical expression was derived by means of regression analysis method using the results obtained from the experiments performed under these conditions. Then, with the help of this expression, optimum turning parameters for minimum surface roughness were found via Genetic Algorithm (GA).

Estimate of cutting forces and surface roughness in end milling of glass fiber reinforced plastic composites using fuzzy logic system

Abstract Milling glass fiber reinforced plastic (GFRP) composite materials are problematic, owing to, e.g., nonhomogeneous and anisotropic properties and effects of plastic deformation. To reduce these problems, the effects of cutting speed, feed rate, and the number of flutes on surface roughness and of thrust forces occurring during the milling of GFRP composite materials were investigated by both experimental and fuzzy logic models. Experiments were performed at 30 m/min, 60 m/min, and 90 m/min cutting speeds, at 0.1 mm/rev, 0.15 mm/rev, and 0.2 mm/rev feed rates and 10 mm diameters in a cemented carbide end mill, which has two, three, and four flutes without cutting fluids. The values obtained from experiments were defined by a fuzzy logic model. A fuzzy logic model was employed to estimate the surface roughness and thrust forces for different cutting parameters. As a result of both the experimental study and the fuzzy logic model, while the minimum thrust force was obtained at low cutting speeds, and feed rates and a high number of flutes end mill, the best surface quality was obtained at low feed rates, high cutting speed, and number of flutes end mill.

A study on machinability of Al Si7 Mg2/SiCp metal matrix composite

This paper presents the result of an experimental investigation on the machinability of silicon carbide (SiC) particulate Al Si7 Mg2 Metal Matrix Composite (MMC) during turning using fixed WC insert (TiN coated and uncoated). Al Si7 Mg2 alloy composites contain various particle sizes (10–32 µm) of 15 wt.% SiCp were prepared by squeeze casting method. Optical microscopic examination, hardness, density, tensile strength and impact toughness measurement were carried out. The influence of machining parameters, for example, cutting speed, feed and depth of cut on tool wear and surface roughness were investigated during the experimentation. Test results show BUE is formed during machining of Al Si7 Mg2/SiCp-MMC at low cutting speed, low feed and high depth of cut. In without coolant turning condition, the tool wear was mainly affected by cutting speed, increased with higher cutting speed. Meanwhile, surface roughness was influenced with combination of feed and cutting speed.

THE EFFECT OF DRILLING PARAMETERS ON STRENGTH OF GLASS FIBRE-EPOXY LAMINATES BY PRODUCED HAND LAY-UP

In this study, the effects of delamination factor on strength of glass fiber reinforced plastic (GFRP) composite with +45/-45 orientation angle fabrics were investigated. GFRP composite specimens, which contain 36% fiber volume, were produced by hand lay-up. The all specimens were prepared according to ASTM D5766-2002 standards. The experiments were conducted the different drilling parameters such as cutting speeds and feed rates using tungsten carbide (WC) and Brad Spur drill tools. Delamination factors of drilled specimens were determined by optical microscope. The tensile strength values of the drilled GFRP composite specimens were determined by universal tensile testing machine. As results, it was determined that the increasing cutting speed and feed rate increased the delamination factor. The strength of GFRP composites decreased with increasing delamination factor .

Effect of cutting environment and heat treatment on the surface roughness of drilled Al/SiC MMC

Abstract In the last decades, the use of metal matrix composites (MMCs) has increased enormously in many engineering applications such as aerospace, automotive, marine and railway. Such materials are known as difficult to machine materials due to the presence of very hard and abrasive reinforcements. The purpose of this study is to determine the influence of the cutting parameters, cutting environment and heat treatments on the surface roughness after drilling A 356/15 SiC MMCs. Experiments were conducted at different cutting speeds, feed rates, heat treatments (as-received, solution annealed and aged) and cutting environments (MQL, compressed air and dry). Improved surface roughness values were obtained with increased cutting speeds and decreased feed rates. The surface roughness using the MQL technique was lower than the surface roughness obtained for the other cutting environment. The optimal machining parameter combination has been obtained and the cutting conditions in terms of the cutting speed of 15 m × min−1, the feed rate of 0.1 mm × rev−1 and the cutting environment MQL represent applicable solutions for the annealed materials.