Alper Uysal

Investigation of flank wear in MQL milling of ferritic stainless steel by using nano graphene reinforced vegetable cutting fluid

Purpose In milling of stainless steel materials, various cutting tool failures such as flank wear, crater wear, cracks, chipping, etc. can be observed because of their work hardening tendency and low thermal conductivity. For this reason, this paper aims to develop some coolants and coatings to reduce these formations. However, further research should be performed to reach the desired level. Design/methodology/approach In this study, the initial flank wear rates of uncoated and titanium nitride-coated tungsten carbide cutting tools were investigated during the milling of AISI 430 ferritic stainless steel. The milling experiments were conducted under dry and minimum quantity lubrication (MQL) conditions. Nano graphene reinforced vegetable cutting fluid was prepared and applied by the MQL system. The mixture ratios of nanofluids were selected as 1 and 2 wt.%, and MQL flow rates were adjusted at 20 and 40 ml/h. Findings It was observed that MQL milling with nano graphene reinforced cutting fluid has advantages over dry milling and MQL milling with pure cutting fluid in terms of the initial flank wear. Originality/value This paper contains new and significant information adequate to justify publication. MQL is a new method for vegetable cutting fluid containing nano graphene particles.

Slip-line field modelling of rounded-edge cutting tool for orthogonal machining:

A new slip-line field model and its associated hodograph of rounded-edge cutting tool were developed for orthogonal micro-cutting operation using matrix technique. The new model considers the existence of dead metal zone in front of the rounded-edge cutting tool. The ploughing forces, chip up-curl radii, chip thicknesses, primary shear zone thicknesses and lengths of bottom side of the dead metal zone are obtained by solving the model depending on the experimental resultant force data. The effects of cutting edge radius, uncut chip thickness, cutting speed and rake angle on these outputs are specified.

Effects of cutting parameters on drilling performance of carbon black–reinforced polymer composite

Polymer composite materials can be produced by reinforcing carbon black, carbon fiber, graphite, graphene, metals and metal oxides, nanotubes, and so on. These types of composite materials can be employed in applications demanding electrical conductivity besides high specific strength and stiffness properties of polymer materials. In the literature, there is a lack of knowledge on the examination of drilling of particle-reinforced composite materials. In this study, drilling of pure polypropylene and carbon black–reinforced polypropylene composite material was investigated at different drill point angles, cutting speeds, and feeds. The cutting temperature of drill point and surface roughness of holes were examined. The experimental studies were designed by L27 full-factorial design, and analysis of variance statistical method was performed. According to the results, cutting temperature increased and surface roughness decreased with the increase in the cutting speed and feed and decrease in the drill point angle.

A New Slip-Line Field Modeling of Orthogonal Machining with a Rounded-Edge Worn Cutting Tool

In this study, a new slip-line field model and its associated hodograph for orthogonal cutting with a rounded-edge worn cutting tool are developed using Dewhurst and Collinss matrix technique. The new model considers the existence of dead metal zone in front of the rounded-edge worn cutting tool. The ploughing force and friction force occurred due to flank wear land, chip up-curl radius, chip thickness, primary shear zone thickness and length of bottom side of the dead metal zone are obtained by solving the model depending on the experimental resultant force data. The effects of flank wear rate, cutting edge radius, uncut chip thickness, cutting speed and rake angle on these outputs are specified.

Metallographic Analysis of the Dead Metal Zone In Metal Cutting With a Rounded-Edge Tool

Abstract The experimental results show that a small dead region is seen in front of the rake face during cutting with a rounded-edge cutting tool. Although this fact was accepted, metallographic analysis of the dead metal zone had never been conducted. A quick stop device was used to obtain chip root samples that are representative of the deformation taking place during dynamic (actual) cutting conditions. A metallographic analysis was performed on selected specimens to identify the microstructure and formation. The photomicrographs were analyzed and an effort made to explain the dead metal zone microstructure.

A Slip-Line Approach to the Micro-Cutting Process with a Rounded-Edge Tool

The effect of tool edge roundness attracts growing attention due to increasing applications of precision, micro-and nanomachining technologies. A new slip-line model and its associated hodograph are proposed for cutting with a rounded-edge tool in this paper. New model considers stagnant metal region called as dead metal zone formed in front of the rake face of tool during cutting process. Dewhurst and Collinss [ matrix technique for numerically solving the slip-line problem is employed in the mathematical formulation of the new model. The unknown slip-line angles were solved depending on the force data obtained from experiments and variation of the sub-regions with cutting edge radius was determined.

Accuracy estimation in drilling small holes on engineering plastics by a mathematical approach

Engineering plastics have wide applications in different fields of industry due to their light weight and easy shaping. In manufacturing multi-component products, assembly is an inevitable stage and drilling is one of the necessary processes before joining of the components of these products. In this study, two of the most common types of engineering plastics, polyacetal (POM) and cast polyamide (castamide), were drilled with twist drills of 0.5 mm and 1 mm diameters, under different cutting speeds and feeds. In determining the accuracy of the drilled small holes, a mathematical approach was used in which least square circle method was applied and radial error of the each drilled hole was obtained. Thus, the hole accuracy could be determined without measuring equipment such as coordinate measurement machine. It has been seen that POM gave better hole accuracy than cast polyamide due its thermal and tribological properties. The effects of feed and cutting speed on the radial error were also investigated. POM did not show apparent difference in radial error according to the cutting parameters while cast polyamide showed lower radial error in higher feeds with 0.5 mm of drill tool and lower radial error with 1 mm of drill tool. Additionally, the radial error could be reduced with decrease of spindle speed at higher feed.

Effects of nano graphene particles on surface roughness and cutting temperature during MQL milling of AISI 430 stainless steel

Abstract Stainless steel is hard-to-cut due to its material specifications and many problems are encountered machining it. Nevertheless, stainless steel is frequently preferred in industry and its use increases. In this experimental study, the machining of AISI 430 ferritic stainless steel under dry, MQL (minimum quantity lubrication) and nanofluid MQL milling conditions was investigated. Nanofluids were prepared by adding 1 wt.-% and 2 wt.-% nano graphene to commercial vegetable cutting fluid. In these experiments, uncoated WC (tungsten carbide) and TiN (titanium nitride) coated WC cutting tools were used and MQL flow rates were selected as 20 ml × h−1 and 40 ml × h−1. Surface roughness and cutting temperatures were measured and the effects of using nanofluid, MQL flow rate, and TiN coated cutting tools were specified. According to the experimental results, the MQL method was shown to be beneficial for reducing cutting temperature and surface roughness values and the nanofluid MQL yielded minimum values. Moreover, TiN coating and an increased MQL flow rate decreased cutting temperature and surface roughness.

Influence of cutting temperature when drilling carbon black reinforced polyamides

Abstract Polymer materials have many fields of application, such as in agriculture and agribusiness, medicine, consumer science, the automotive industry, for sports equipment etc. These materials are generally produced by injection molding, in-mold shaping and extrusion. A machining process is essential however both for small quantity production for complex and accurate shapes. Moreover, it is known that the demand for machining, especially with respect to the drilling of polymer materials has increased. In this study, the cutting temperature for drilling pure polyamide and carbon black reinforced polyamide was investigated as well as the effects of drill point angle, cutting speed, and feed rate on cutting temperature making use of Taguchi and ANOVA statistical methods. Among the selected drilling parameters, the most significant was found to be the drill point angle and the least effective the feed rate.

Evaluation of drilling parameters on surface roughness and burr when drilling carbon black reinforced high-density polyethylene

In this study, surface roughness and burr were investigated in drilling of pure and carbon black reinforced high-density polyethylene at three cutting speeds and feeds with three drill point angles. The measurement results of surface roughness of drilled holes were evaluated by Taguchi and analysis of variance statistical methods to specify the optimal drilling parameters and the effects of selected drilling parameters. According to the results, lower surface roughness and fewer burrs were obtained in drilling at high cutting speed and low feed with drill tools having small point angle and it was specified that the carbon black reinforcement reduced the surface roughness. Additionally, the optimal drilling parameters were determined as drill point angle of 80°, feed of 0.1 mm/rev and cutting speed of 120 m/min and the most effective parameter was found as drill point angle and the least effective parameter was found as feed.