Influence of Machining Characteristics on Ultra-Precision Cutting of Aluminum Alloys

2014 ◽  
Vol 625 ◽  
pp. 201-206
Author(s):  
Daisuke Hirase ◽  
Yukio Maeda ◽  
Kenichi Iwatsuka ◽  
Takanori Yazawa

In this study, we investigated ultra-precision cutting technology used in the production of Al alloy polygon mirrors. We compared characteristics of three Al alloys (Al–Mg, Al–Cu, and Al–Si) when cut with a straight diamond tool. When cutting Al alloys, it is desirable to reduce geometric surface roughness and remove tear-out marks and scratch marks. We investigated the relationship between end cutting edge length, surface roughness, and cutting force of straight diamond tools. In addition, we compared surface roughness and cutting force produced by double facet tools with microfacets at the end cutting edge and on the rake-face side. It was found that both tools have similar cutting characteristics and that Al–Mg has the best optical quality, followed by Al–Cu and Al–Si.

2005 ◽  
Vol 291-292 ◽  
pp. 475-482 ◽  
Author(s):  
Koichi Okuda ◽  
Masayuki Nunobiki

This study aims at clarifying the relationship between the surface integrity of PTFE finished by an ultra-precision diamond cutting and the adhesion strength of a metal thin film. As the first step of this study, the basic properties such as surface integrity in the diamond cutting of PTFE and the effect of the surface roughness on the textile water repellency are demonstrated in this report. The following remarks were found. The measured roughness of finished surface largely exceeded the theoretical roughness, while the cutting force was very small comparing with aluminum and the flow type chips were formed. The surface with a smaller roughness tended to repel water.


2015 ◽  
Vol 656-657 ◽  
pp. 302-307
Author(s):  
Tomohiro Iida ◽  
Yukio Maeda ◽  
Daisuke Hirase ◽  
Kazuhide Kamiya ◽  
Hideaki Tanaka ◽  
...  

Recently, increasingly high efficiency and high performance have become to be required of information equipment. As a result, optical scanning parts that reduce optical aberrations, scatter, and diffraction are required in laser printers. It is therefore necessary to improve the geometric surface roughness achieved in mirror cutting of Al alloys and eliminate tear-out marks and scratch marks that can be created during the cutting process. In this study, we investigated the effect of tool wear on the occurrence of surface discontinuities in ultra-precision cutting of Al alloys. In our previous studies, a crystal orientation of {110} plane was adopted in cutting an Al-Si alloy (AHS material, 11wt% Si) and Al-Mg alloy (A5186 material, 4.5wt% Mg) using a straight diamond tool. The cutting edge recession that occurs when cutting AHS material has been reported to be approximately 5 times greater than that which occurs when cutting A5186 material. Therefore, we cut the AHS material for accelerated wear and investigated the cutting edge recession, the surface roughness and the cutting force. We found that the cutting edge recession decreases as the tool wear angle γ increase. For example, at a tool wear angle γ = 40°, the cutting edge recession is approximately 7 times greater than that which occurs at a tool wear angle γ = 12°. As the tool wear angle increases, the cutting distance increase, which produces a mirror like surface. In addition, we were able to obtain a good machined surface using a positive tool setting angle because side cutting edge produces residual stock of removal 0.1 μm when the cutting edge recession is 0.3 μm or more and when it is cut by following end cutting edge.


2006 ◽  
Vol 304-305 ◽  
pp. 8-13 ◽  
Author(s):  
T. Jin ◽  
D.J. Stephenson

Optical surface finish below Ra 10nm can be achieved on a ‘Tetraform C’ grinder of ultra-high stiffness, when grinding a low alloy steel with or without the help of ELID (electrolytic in process dressing). Surface roughness generation modelling has been carried out to predict thepossible surface roughness values. Efforts have been made to transfer the process knowledge to different grinding mode using a rigid 5-axis Edgetek CNC grinder. The effects of material removal rate and grit size and also that of spark out passes on the surface roughness generated have been investigated.


2014 ◽  
Vol 625 ◽  
pp. 437-445 ◽  
Author(s):  
Zhuo Lin Li ◽  
Wing Bun Lee ◽  
Benny C.F. Cheung ◽  
L.T. Ho ◽  
Yue Gang Fu

Reflecting lens is an important component of optical systems, such as high-resolution cameras, large space telescopes and meteorological satellites etc. Among the lens materials, Silicon Carbide (SiC) has attracted a lot of attention as an important optical material because of its excellent mechanical and physical properties. Apart from the form accuracy, the attainment of a consistently high optical quality in polishing SiC is still of a concern. There are advanced ultra-precision polishing machines that can correct geometrical errors and surface finish of the workpiece. These include surface roughness and waviness. However, the hardness of SiC material itself put an challenge for polishing process. In this paper, A computer controlled ultra-precision polishing (CCUP) method based on mechanical polishing is used to produce the SiC lens. Experiments are being designed on a 7-axis ultra precision polishing machine (Zeeko IRP200). As it is difficult to find out slurry which is harder than SiC so that the conventional polishing slurry is be used. It provides a nice consequence that it also efficient when the polish powder is softer than the machined materials. The tool pressure, polishing head speed and the feed rate are varied and optimized to obtain the best reflectivity of the lens being polished. A pilot experiment will be conducted for the corrective polishing for the form error of the optical surface made of SiC. The result from the study will provide an important means to optimize the process for machining SiC reflective lens using the CCUP process.


1998 ◽  
Vol 4 (S2) ◽  
pp. 510-511
Author(s):  
S. J. Lee ◽  
E.S. Hwang ◽  
T. Dolukhanyan ◽  
C. M. Sung

Al films have been deposited on the inside of the Color Display Tube (CDT) panel on which black matrix carbon and RGB phosphors were coated to improve brightness with the prevention of voltage down and less ion impact to phosphors. The characteristics of Al films have a close relationship with the deposition variables such as base pressure and deposition rate causing changes in Al film microstructures and differences in the reflectance. It is generally known that the reflectance is affected by the thickness, grain size, and surface roughness of the Al film: The grain size of the Al film tends to decrease when base pressure is poor due to the presence of residual gas. The reflectance of Al alloys was reported to be increased with the larger grain size.The purpose of this study is to understand the relationship between the reflectance and the microstructures of Al films as a function of base pressure in a CDT manufacturing to optimize deposition conditions for improved reflection properties.


2012 ◽  
Vol 516 ◽  
pp. 551-556
Author(s):  
Thanh Hung Duong ◽  
Kim Huyn Chul ◽  
Lee Dong Yoon

In recent years, there have been many studies concerning the effect of cutting parameters and tool parameters on the ultra precision machining of electroless nickel. However, there is no known reported study on the relationship between the cutting force and tool rake angle in ultra precision machining of electroless nickel. The objective of this study is to compare and investigate the cutting force with various rake angles for micro machining electroless nickel work pieces by theoretical analysis and experiment. Diamond tools with rake angles of-10o, 0o and 10o were used in the experiment. According to theoretical analysis, the tool with a 10o rake angle induces the smallest cutting force. However, the experiment showed that the tool with zero rake angle always gave us the smallest cutting force for all cutting speeds, cutting depths and pattern pitches.


2012 ◽  
Vol 565 ◽  
pp. 359-364 ◽  
Author(s):  
Masahiro Furuno ◽  
Koichi Kitajima ◽  
Takeshi Akamatsu

The results of an investigation on the effects of surface roughness on ball end mill are reported here. We used grindwheels with varying in grit between #325 and #1000 to grind ball end mill’s rake surface and flank surface, and then coated the end mill with TiAlN film, CrSiN film, and TiSiN film. We measured the state of adhesion on the films on the rake surface in continuous lathe milling as well as the surface roughness and cutting force. The results show that, in generating the cutting cutoff, the optimum grinding roughness differs between the near vicinity of the cutting-edge ridgeline and the part of the rake surface that is further away from the cutting-edge ridgeline. From that fact, we understand that the cutting characteristics of the work material and the surface area of the rake surface that is in contact with the cutting cutoff exert their respective influences during the cutting.


Química Nova ◽  
2021 ◽  
Author(s):  
João Araujo

THE ANODIZING PROCESS OF ALUMINUM AND ITS ALLOYS: A HISTORICAL AND ELECTROCHEMICAL APPROACH. Al and its alloys are found in several industrial applications. However, like most metals, this material is not immune to corrosion, being necessary to be protected against corrosion. One of the methods most commonly employed to improve the corrosion resistance of Al alloys is the anodizing process, which consists of thickening of the natural oxide (Al2O3) presents in Al through anodic oxidation. The anodizing process is accomplished by immersion of the Al alloy into an acid bath and passing an electric current through it. This process produces two layers: a barrier layer thicker than the natural oxide and a layer with regular arrangement of nanopores (porous layer). This duplex structure forms the anodized layer with a large specific surface area. With the advent of nanotechnology, this layer has been applied in other areas due to its low cost, stability, absence of toxicity, and biocompatibility. In this context, this paper addresses a historical and electrochemical review of the anodizing process of Al and its alloys, presenting the main events that culminated in the development of the current processes and the understanding of the relationship between the chemical reactions and the mechanisms that occur during nucleation and development of the oxide layer


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 8172-8183
Author(s):  
Dong Jin ◽  
Kejun Wei

Scots pine (Pinus sylvestris L.) is a fast-growing wood that has been widely manufactured into various furnishing products. To improve the machinability of Scots pine, the cutting force and surface roughness during peripheral milling with helical cutters was assessed via an orthogonal experimental design. Experimental results revealed that the resultant cutting force is positively related to the depth of cut, but negatively correlated with inclination angle of cutting edge and cutting speed. However, surface roughness first declines and then increases with increasing inclination angle, and it also shows an increasing trend with the increasing depth of cut and decreasing cutting speed. Furthermore, the depth of cut significantly contributes to the resultant force and surface roughness, while both the cutting speed and inclination angle have insignificant impacts on the resultant force and surface roughness. Finally, the optimized milling parameters were determined as 62° inclination angle of cutting edge, 45 m/min cutting speed, and 0.2 mm depth of cut, and these parameters are proposed for the quality finishing of Scots pine machining.


2012 ◽  
Vol 565 ◽  
pp. 382-387
Author(s):  
Kazuki Imazato ◽  
Koichi Okuda ◽  
Hiroo Shizuka ◽  
Masayuki Nunobiki

This paper deals with finish cutting of thermally affected layer on cemented carbide by a diamond tool in order to machine efficiently the carbide mold with high accuracy and good surface without a polishing. The microstructure of thermally affected layer left by EDM process was observed and analyzed by EPMA. Its hardness and thickness were measured. Subsequently, the cutting experiments were carried out by using a PCD tool and an ultra-precision cutting machine. The effects of the thermally affected layer on the surface roughness, the cutting force and the tool wear were investigated. As a result, it was confirmed that the cutting force decreased with an increase in the depth of cut. Furthermore, it was found that the tool wear and the surface roughness obtained by cutting the thermally affected layer were greater than those of the original workpiece.


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