Papers by Keyword: Cutting Edge

Abstract: Residual stress measurements directly in the coated cutting edge are not possible with X-ray diffraction (XRD) due to the diameter of the X-ray beam. On the other hand, Raman microscopy enables measurements on the micrometer scale. Parameter variations in the PVD process were used to provide different residual stress states in (Al,Ti)N coatings on carbide cutting tools. They were examined by XRD in regions that can be reliably measured. The same area was then examined by Raman microscopy to determine the relationship of Raman peaks to the residual stress. Local high-resolution Raman measurements were then taken at the cutting edge and further influences on the Raman peak position besides residual stresses were excluded. In order to analyze the relationship between Raman peak shift and residual stress state, measurements were performed during a bending load. Finally, an outlook on further investigations is given.

Abstract: The economic application of various cutting processes in product development can lead to significant forming problems when changing from prototypes to serial parts. Every cutting process causes characteristic effects on the resulting edge and consequently specific edge cracking sensitivities. For exterior trim components of premium car models various bright finishing alloys are used but were not yet focus of scientific research. Within this study influences of laser beam cutting and machining on the edge cracking sensitivity of the alloys Al99.7Mg0.8Cu and EN AW-5505 are analyzed by executing hole expanding tests according to ISO 16630 enhanced with an offline evaluation method. To assess possible impacts on the resulting hole expansion ratios material and edge characterizations are conducted. Generated knowledge can support reducing forming problems occurring while changing from prototypes to serial parts.

Abstract: It is very important that a grinding tool surface topography is measured and analyzed. In this paper, a line scan camera is installed in our three dimensional measurement system by shortening a measurement time. In this experiment, a diamond grinding wheel SD140Q100M is employed. As a result, the time can be reduced to about 24[s] from 1380[s]. On the other hand, a voronoi diagram is introduced as an evaluation method of a distribution of cutting edges on the grinding tool. According this method, the dispersion can be visualized. Furthermore, it is found that the voronoi region has a relation to a protrusion height of the cutting edge.

Abstract: High mechanical impact loads in interrupted or inhomogeneous machining processes frequently lead to spontaneous fracture of the cutting edge. Even modern cutting materials cannot provide a combination of high enough hardness and toughness that is capable of preventing this sort of tool failure. Such machining conditions therefore remain difficult and further investigations, aiming to reduce the impact load of the cutting tool in order to enhance tool-life, are necessary. A simulation model of the impact situation, that serves to optimize a force conducting structure with regard to elasticity, damping properties and resulting force peaks, was developed and is presented in this paper. Furthermore measurement devices were composed that are needed for high-resolution recording of impact forces without repercussions and for verification of the elaborated simulation model. It could be shown that mechanical damping of the cutting tool can lead to reduced impact forces on the cutting edge, which in turn should lead to longer tool life.

Abstract: The origin of drilling force in drilling with twist drill is quite complicated owning to the complex shape of the drill bit cutting edges. In this paper, the drilling experiments both with and without the ultrasonic were designed and conducted on aluminum alloy with pre-drilled hole. The drilling force was tested and the different effects between the cutting edges of the twist drill on the drilling force were analyzed under various drilling parameters including the spindle speed, feed rate and vibration amplitude. The drilling force of conventional drilling (CD) and ultrasonic assisted drilling (UAD) was characterized and the roles of the ultrasonic vibration in drilling were discussed.

Abstract: The wear properties of steel dental curettes coated with wear resistant Diamond Like Carbon (DLC) and metal nitride coatings deposited by Physical Vapor Deposition (PVD) were studied by using a customized mechanical device simulating motion and load of dental curettes against human teeth. The wear surfaces were studied by optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Nanoindentation. Rockwell indentation testing was used to evaluate the coating adhesion. With the optimized combination of substrate steel and wear resistant coating reduction of 80% in the wear of instruments could be achieved.

Abstract: The ball nose end milling process, which use a ball nose cutter, is very complex and, generates a pronounced area variation of the cross section in the uncut chip. In this sense, the current paper looks into and assesses some aspects regarding the geometric simulation of the chip generating mechanism in 5 axes ball nose end milling. The influence of tool inclination, however, was not considered in the machining strategy, starting with the tool path program in CAM software, which allows the management of various ways of tool path generation, but cannot decide which one is the best. The present study advances, with minimal approximation, a geometrical method to establish the volume of the uncut chip and area variation of the cross section, obtained in 3D-CAD by four surfaces intersection [1]. Both rotations in 5 axes are considered for the tool and degree range is 0 to 30 for rotary axis A and 0 to-30 for rotary axis B (A+B-in fourth geometrical quadrant).

Abstract: Take commonly used materials Cr12MoV for automobile panel mold as object of study, using the finite element simulation software ABAQUS, take the node displacement direction as the criterion of the chip formation, determine the minimum cutting thickness of Cr12MoV materials under different tool edge radius values, this value is determined to selection and optimization of mold steel milling finishing machining allowance provides a theoretical basis.

Abstract: Generally, the indexable inserts carry out work with arc transition edges, which have a wiping effect on surface under processing and reduce the roughness of the surface. [ However, existing literatures lack research on the forming of arc transition edge surface. In this paper, the unified mathematical model and forming methods of different arc transition edge surfaces were presented, which can be used for other forming process. The mathematic models deduced would lay the most important foundation for manufacturing indexable inserts automatically. The models presented could also be extended for study on some complicated transition surfaces. Finally, the simulation was done and the result verified the theoretical derivation.

Abstract: The paper shortly illustrates the general concept of Reverse Engineering, which includesalso the 3D scanning. In the main part of the paper the concrete 3D scanning process of chosen individual objects are described. The problems that occurred during 3D digitizing of individual parts are step by step discussed and solved. The paper deals with 3D scanning of ball nose end mills and screw drill. The article gives a procedure for digitizing and comparing the results of the scanned digital models of the two ball nose end mills and screw drill.