scholarly journals Estimation of Machined Surface Texture Being Based on Cutter Run-out Trajectory and Cutting Edge Profile of Small Diameter End-mill (1st Report)

2009 ◽  
Vol 75 (5) ◽  
pp. 645-649 ◽  
Author(s):  
Teppei NEBUKA ◽  
Hidetake TANAKA ◽  
Kazuhisa YANAGI
2019 ◽  
Vol 13 (5) ◽  
pp. 639-647
Author(s):  
Keiji Ogawa ◽  
Takumi Imada ◽  
Haruki Kino ◽  
Heisaburo Nakagawa ◽  
Hitomi Kojima ◽  
...  

The demand for micro-end-milling for products in fields such as the medical, optical, and electronics industry is increasing. However, when machining with a small diameter end-mill (micro-end-mill) with diameters such as 0.5 mm, the rigidity of the tool itself is low; hence, the cutting conditions must be set to low values to achieve stable machining. Therefore, we examined various cutting phenomena that occur during actual machining processes to achieve high machining accuracy, high finished-surface quality, and long tool life. Some studies on micromachining achieved high accuracy, high-grade machining by considering the cutting phenomena. In previous papers, we dealt with the side-cutting phenomena in micro-end-milling of hardened die steels using a high-speed air-turbine spindle with rolling bearing. Cutting experiments were carried out by measuring the cutting force and flank wear of a cutting tool to investigate the difference in cutting phenomena caused by cutting direction in high-speed micro-end-milling. Observation of the machined surface and measurement of the profile of the cutting edge and machined surface were demonstrated. It was revealed that machining quality in high-speed up-cut milling was better than that in down-cut milling. Shoulder cutting, in which both peripheral and bottom cutting edges act simultaneously on the workpiece, was also investigated. A novel small diameter end-mill with left-hand helical tool with right-hand cut was developed to avoid damaging the cutting edge in the initial cutting stage. In the present study, high-quality shoulder cutting of a vertical wall using the new tool was proposed and demonstrated.


2020 ◽  
Vol 846 ◽  
pp. 122-127
Author(s):  
Gandjar Kiswanto ◽  
Yolanda Rudy Johan ◽  
Poly ◽  
Tae Jo Ko

Micro products or micro components are commonly used in today’s world. Research around micromanufacture technologies to produce a better product quality has been going on extensively. Ultrasonic vibration assisted micromilling (UVAM) is one of the technologies that can give a better machining qualities over the conventional ones. One of the benefits UVAM can give is reducing the machined surface roughness. The purpose of this paper is to give an idea how vibration assisted micromilling can give a better surface roughness quality. The theoritical surface roughness geometry model is made using MATLAB software. The cutting tool used in the simulation is end mill. There is a feature of the cutting tool called bottom cutting edge angle. This feature will be considered on this paper. The effects of the bottom cutting edge on workpiece machined surface can be looked visually from the simulation. Thus, the effects of cutting process using UVAM on the workpiece surface can be looked as well through the simulation.


2014 ◽  
Vol 21 (1) ◽  
pp. 145-156 ◽  
Author(s):  
Szymon Wojciechowski ◽  
Paweł Twardowski ◽  
Michał Wieczorowski

Abstract In this paper, an analysis of various factors affecting machined surface texture is presented. The investigation was focused on ball end mill inclination against the work piece (defined by surface inclination angle a. Surface roughness was investigated in a 3D array, and measurements were conducted parallel to the feed motion direction. The analysis of machined surface irregularities as a function of frequency (wavelength A), on the basis of the Power Density Spectrum - PDS was also carried out. This kind of analysis is aimed at valuation of primary factors influencing surface roughness generation as well as its randomness. Subsequently, a surface roughness model including cutter displacements was developed. It was found that plain cutting with ball end mill (surface inclination angle a= 0°) is unfavorable from the point of view of surface roughness, because in cutter’s axis the cutting speed vc ~ 0 m/min. This means that a cutting process does not occur, whereas on the machined surface some characteristics marks can be found. These marks do not appear in case of a* 0°, because the cutting speed vc * 0 on the fill I length of the active cutting edge and as a result, the machined surface texture is more homogenous. Surface roughness parameters determined on the basis of the model including cutter displacements are closer to experimental data for cases with inclination angles a* 0°, in comparison with those determined for plain cutting (a= 0°). It is probably caused by higher contribution in surface irregularities generation of plastic and elastic deformations cumulated near the cutter’s free end than kinematic and geometric parameters, as well as cutter displacements.


Author(s):  
Ramesh Kuppuswamy ◽  
Kapui Mubita

Electro-polishing was used as an alternative to mechanical polishing for the cutting edge preparation of tungsten carbide (WC) ball nose end mills. High-quality cutting edge surfaces with roughness of magnitude 0.3–0.35 µm was achieved using the electro-polishing process. A direct current of 0.96 A was passed through an electrolytic cell containing the electrolyte sodium hydroxide with a concentration—2.5 mol/dm3. The ball nose end mill was suspended as the anode and a stainless steel (SS304) as the cathode. The ball nose end mill was electro-polished using the optimized parameters which was obtained through performing the preliminary experiments on tungsten carbide coupons of size D6 × 20 mm. The effects of electro-polishing on the surface texture of the ball nose end mill were determined using surface texture examinations. Machining tests were conducted on Ti6Al4V alloy to understand the growth of flank wear on the electro-polished ball nose end mills. After every 5 m of cutting distance, flank wear measurements were done for both the regular ball nose end mill and the electro-polished ball nose end mills. The results revealed that the electro-polished ball nose end mill reached a flank wear of 0.15 mm after a cutting distance of 550 m. This was significantly more than the cutting distance of the standard ball nose end mill of magnitude 350 m for the same amount of flank wear. This showed an increase in tool life of over 50%.


2020 ◽  
Vol 14 (1) ◽  
pp. 26-37
Author(s):  
Takumi Imada ◽  
Keiji Ogawa ◽  
Haruki Kino ◽  
Heisaburo Nakagawa ◽  
Hitomi Kojima ◽  
...  

This study deals with shoulder cutting phenomena in micro-end-milling of hardened die steel. Demand for micro-end-milling for products in the medical, optical, and electronics industry is increasing. However, in machining with a small diameter end mill that has diameter of e.g., 0.5 mm, the rigidity of the tool itself is low; therefore, cutting conditions must be set to low values to achieve stable machining. We revealed that cutting phenomena became unstable because the end cutting edge was damaged early in shoulder cutting. Therefore, we experimentally prepared a left hand helical tool with a right hand cut to perform complete processing by improving the strength of the end cutting edge. Cutting experiments were carried out while measuring cutting force and observing cutting phenomena, end cutting edge, and machined surface via scanning electron microscopy (SEM). We determined the effects of such tools on fundamental phenomena in shoulder cutting with a small diameter end mill. The rake angle of the tool was improved based on experimental analysis of the damage mechanism of the cutting edge in the shoulder cutting. A result of the examination to investigate the influence of the difference in rake angle on chip evacuation showed that the chip discharge direction was affected by the rake angle; when the angle is blunt, the chips were discharged upward, and the chip discharge performance improved.


1986 ◽  
Vol 52 (10) ◽  
pp. 1746-1751
Author(s):  
Noriteru NISHIDA ◽  
Makoto KAWANO ◽  
Yasuhiko OOGIYA

2018 ◽  
Vol 8 (8) ◽  
pp. 1353
Author(s):  
Tao Chen ◽  
Fei Gao ◽  
Suyan Li ◽  
Xianli Liu

Carbon fiber reinforced plastic (CFRP) is typically hard to process, because it is easy for it to generate processing damage such as burrs, tears, delamination, and so on in the machining process. Consequently, this restricts its wide spread application. This paper conducted a comparative experiment on the cutting performance of the two different-structure milling cutters, with a helical staggered edge and a rhombic edge, in milling carbon fiber composites; analyzed the wear morphologies of the two cutting tools; and thus acquired the effect of the tool structure on the machined surface quality and cutting force. The results indicated that in the whole cutting, the rhombic milling cutter with a segmented cutting edge showed better wear resistance and a more stable machined surface quality. It was not until a large area of coating shedding occurred, along with chip clogging, that the surface quality decreased significantly. At the stage of coating wear, the helical staggered milling cutter with an alternately arranged continuous cutting edge showed better machined surface quality, but when the coating fell off, its machined surface quality began to reveal damage such as groove, tear, and fiber pullout. Meanwhile, burrs occurred at the edge and the cutting force obviously increased. By contrast, for the rhombic milling cutter, both the surface roughness and cutting force increased relatively slowly.


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