THE DESIGN MODEL OF MICRO END-MILLS MADE BY USING THE FINITE ELEMENT METHOD

The green processing technology has been brought to the focus of attention around the world. The development and application of green cutting depend on the machine and cutting tool technology progress, in so far as the development of cutting tool technology has quite a big influence. The study was focused on the simulation analysis model for micro milling SKD61 tool steel developed by the finite element method. First, because the impact of the effective rake angle on the oblique cutting model is equivalent to that of the rake angle on the orthogonal cut model, the complex tool geometry of an end-mill will be simplified to the orthogonal cutting model. Using the Taguchi method, the FEM simulation of orthogonal cutting operation was performed under different cutting speeds, cutting depths, effective rake angles and relief angles were modified. The cutting force, tool maximum temperature, tool maximum temperature and tip distance, and the contact length of tool and chip are the major performance indexes of micro milling process. Finally, the multiple cutting performance characteristic resulting from the grey relational analysis reveals that the influencing priority ranks for micro end-mills made of SKD61 tool steel are cutting speed, effective rake angle, relief angle, and cutting depth. The FEM model is suitable for simulating the cutting performance of micro cutting process, and can also be used as a design base for micro endmills

Prediction Model of End Mill Cutting Edge Based on Material Properties and Cutting Conditions

In machining, the cutting performance of the tool depends on the tool material, tool structure, tool geometry, properties of workpiece materials, and cutting conditions. If the user chooses an inappropriate cutting tool for the machining of the workpiece material, this will cause energy loss and severe tool wear. This study aims to investigate the influence of mechanical properties of workpiece material and cutting conditions on the tool geometry and to establish a polynomial network for the prediction of a reasonable normal relief angle and a normal wedge angle based on experimental data. Experimental results indicate that the cutting of high hardness and high strength workpiece materials requires a larger normal wedge angle to increase the cutting edge strength. In addition, the design of the normal relief angle is related to Young\u27s modulus and the toughness of the workpiece material, mainly to avoid material elastic recovery during the cutting process. In terms of cutting parameters, as the radial depth of cut increases, the contact area between the tool and the chip increases, which causes the heat to concentrate at the tip of the tool; hence, it is necessary to increase the normal wedge angle. In addition, the feed per tooth had a negligible effect on the normal wedge angle. Finally, the prediction model was verified by five untested workpiece materials. The results of the cutting tests showed that the flatness of the cutting edge was less than 15 μm, which indicates that a normal cutting phenomenon occurred on the flank

Development of inspection system for tool presetter

In order to conform to the concept of smart factory for industry 4.0, this paper developed a low-cost tool measuring machine included the structure design, hardware planning of the server, electromechanical control, drive system, human machine interface, communication between hardware and software, software development, and so on. The proposed measuring system provided more flexibility and integration with peripheral equipment for the requirements of industry 4.0. Compared with a Germanic measuring machine, experimental results showed that the percentage of errors of the designed inspection instrument were 0.004 ％ and 0.003 ％ for the tool length and diameter measurements of a square end mill, respectively

Optimization of the optical parameters in Fabry-Perot interferometer

Due to insensitivity to the environmental disturbances, Fabry-Perot interferometers are suitable for displacement measurements under ordinary conditions. In the structure of folded Fabry-Perot interferometer, the results of the signal subdivision are affected by the optical parameters in the resonant cavity. In this paper, the analysis of the Fabry-Perot interferometer for the measurement of the micro-displacement and the long-distance are investigated. By considering the reflectance of the planar mirror and the intensity loss in the resonant cavity, the parameters of systematic optimization which are suitable for the measurement of the micro-displacement and the long-distance are proposed. The experimental and simulated results reveal that the intensity loss in the resonant cavity is 86% and the optimized reflectance of the planar mirror is 12%

Evasion of anti-growth signaling: a key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally-occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally-occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting

Measurement of the top quark mass using the matrix element technique in dilepton final states

We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7  fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84  GeV