Erhan Altan

Influence of Filler Amount and Content on the Mechanical Performance of Joints Bonded with Metal Powder Filled Adhesive

The objective of this study is to investigate the surface roughness that effect the capability of adhesive with adding aluminium powder and 63/37 Sn-Pb soft solder powder to the epoxy to increase the mechanical strength of joints. The adhesive strength of the joints was determined by utilizing the single-lap shear test. As seen from the experiments, the surface roughness has an important effect on the strength of adhesive bonded joints. Experimental results show that joints prepared by adhesive which was modified, adding in the amount of 5 wt% 63/37 Sn-Pb powder have more mechanical strength than joints compared to one which is prepared by adding aluminium powder with different ratios as 5, 25,50 wt%.

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.

Position of the separation point in machining with a rounded-edge tool

In this article, the effect of separation point on metal flows and the behavior of the material in front of the tool face with a rounded-edge tool are experimentally examined. The character of metal flow near the rake face has obvious significance to the partial problems of the surface finish and accuracy. Analysis of variance is used to determine the most significant parameter for the separation point height from the machined surface. As the distance between the separation point and the machined surface increased, the cutting edge radius grew. It is demonstrated through experiments that the edge radius of the cutting tool affects the machining and material flow process.

A new hybrid bonding technique: Adhesive-soft soldered joints

Joining of components is usually accomplished by mechanical fastening, welding, or adhesive bonding. Apart from the classical methods, various hybrid methods applied with adhesives are widely used in industry to bond mechanical parts. This study describes a new hybrid bonding method as an alternative to currently used hybrid methods: adhesive-soft soldered joints. In this new hybrid technique, joints are made by adding various (5 wt%, 15 wt%, 25 wt%, and 50 wt%) amounts of soft soldering alloy powder into the adhesive at two different temperatures (180℃ and 200℃). The strength of the joints is measured by tensile shear tests. The mechanical strength of adhesive joints carried out by adding soft soldering powder melted at 200℃ is higher than that of joints with only adhesives and unmelted soft soldering powders. The developed hybrid method is applied to attach the insert to cutting tools used in the machining industry and the feasibility of the method is investigated with experiments.

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.

Design of a computer aided quick-stop device for study of dead metal zone formation

The use of quick-stop device allows observing a sequence of frozen images focused on the chip formation area when machining in orthogonal turning tests. This work records the development of a quick-stop device employing a servo motor. The present invention relates generally to a quick stop device, for combination with a cutting machine that is able to abruptly interrupt the cutting process between a cutting tool and the surface being cut. A dead metal zone is clearly seen when using rounded-edge cutting tools. In this study, variation of the dead metal zone is examined with the computer aided quick-stop device (CAQSD). It is clear from the experimental photomicrographs that as the cutting edge radius increases, dead metal zone increases.

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.

An experimental study on dead metal zone in orthogonal cutting with worn rounded-edge cutting tools

A dead metal zone is formed by the negative rake angle effect of the rounded-edge and it affects the cutting forces during machining operations. Therefore, investigating the size of the dead metal zone and changing it with cutting edge radius and flank wear rate are important. In this study, the dead metal zone was investigated experimentally for unworn and worn rounded-edge cutting tools and it was defined by changing the flank wear rate and cutting edge radius. It was observed that the size of the dead metal zone increased with increase of the cutting edge radius and it became smaller with increasing the flank wear rate. In addition, cutting force and thrust force were investigated. It was proven that both forces increased with increase of the cutting edge radius and the flank wear rate.

Experimental investigation of a slip-line field model for a worn cutting tool

In this study, the slip-line field model developed for orthogonal machining with a worn cutting tool was experimentally investigated. Minimum and maximum values of five slip-line angles (θ1, θ2, δ2, η and ψ) were calculated. The friction forces that were caused by flank wear land, chip up-curl radii and chip thicknesses were calculated by solving the model. It was specified that the friction force increased with increase in flank wear rate and uncut chip thickness and it decreased a little with increase in cutting speed and rake angle. The chip up-curl radius increased with increase in flank wear rate and it decreased with increase in uncut chip thickness. The chip thickness increased with increase in flank wear rate and uncut chip thickness. Besides, the chip thickness increased with increase in rake angle and it decreased with increase in cutting speed.