High Speed Machining Method of Large-Size Precision Freeform Mirror

2014 ◽  
Vol 1017 ◽  
pp. 340-343 ◽  
Author(s):  
Okiharu Kirino ◽  
Hiroyuki Nakagawa ◽  
Shigeru Kirino ◽  
Hirokazu Kataza

This study describes the non-rotationally symmetric diamond turning (XZC turning) for producing large-size precision freeform mirror. This is a high speed machining method as compared with the traditional XYZ diamond milling or fly-cutting. Moreover, the application of this method is a key factor in the development of the ultra-precision light-weight freeform mirror for outer space use. This report introduces these cutting-edge approaches.

Author(s):  
Mohamed Aly ◽  
Karim Hamza ◽  
Mohammed Tauhiduzzaman ◽  
Mouhab Meshreki ◽  
Ashraf O. Nassef ◽  
...  

Optimum selection of cutting conditions in high-speed and ultra-precision machining processes often poses a challenging task due to several reasons; such as the need for costly experimental setup and the limitation on the number of experiments that can be performed before tool degradation starts becoming a source of noise in the readings. Moreover, oftentimes there are several objectives to consider, some of which may be conflicting, while others may be somewhat correlated. Pareto-optimality analysis is needed for conflicting objectives; however the existence of several objectives (high-dimension Pareto space) makes the generation and interpretation of Pareto solutions difficult. The approach adopted in this paper is a modified multi-objective efficient global optimization (m-EGO). In m-EGO, sample data points from experiments are used to construct Kriging meta-models, which act as predictors for the performance objectives. Evolutionary multi-objective optimization is then conducted to spread a population of new candidate experiments towards the zones of search space that are predicted by the Kriging models to have favorable performance, as well as zones that are under-explored. New experiments are then used to update the Kriging models, and the process is repeated until termination criteria are met. Handling a large number of objectives is improved via a special selection operator based on principle component analysis (PCA) within the evolutionary optimization. PCA is used to automatically detect correlations among objectives and perform the selection within a reduced space in order to achieve a better distribution of experimental sample points on the Pareto frontier. Case studies show favorable results in ultra-precision diamond turning of Aluminum alloy as well as high-speed drilling of woven composites.


2021 ◽  
Author(s):  
Arnab Das ◽  
Shashank Shukla ◽  
Mohan Kumar ◽  
Chitransh Singh ◽  
Madan Lal Chandravanshi ◽  
...  

Abstract The demand of ultra-precision micro-machine tools is growing day by day due to exigent requirements of miniaturized components. High accuracy, good dimensional precision and smooth surface finish are the major characteristics of these ultra-precision machine tools. High-speed machining has been adopted to increase the productivity using high-speed spindles. However, machine tool vibration is a major issue in high-speed machining. Vibration significantly deteriorates the quality of micro-machining in terms of dimensional precision and surface finish. This paper describes a design methodology of a closed type machine structure for vibration minimization of a high-speed micro-milling center. The rigid machine structure has provided plenty of stiffness and the damping capability to the machine tool without utilizing vibration absorbers . The models of the machine structures have been generated and assembled in AutoCAD 3D . The performances of the integrated micro-milling machine tools were determined by finite element analysis. The best model has been selected and proposed for manufacturing. Additionally, simulation results were validated by comparing with experimental results. Eventually, after manufacturing and assembly, experiments have been performed and determined that the amplitude of vibration was approaching towards nanometer level throughout the working range of the high-speed spindle. The machine tool was capable to fabricate miniaturized components with fine surface finish.


2011 ◽  
Vol 230-232 ◽  
pp. 1164-1168
Author(s):  
Chun Jiang Zhou ◽  
Jing Qiao Zou

High speed machining is one of the advanced manufacturing technologies which have developed quickly in recent years. Tool technology is key factor which will make influence to the efficiency and precision of HSM. The paper has analysis the HSM tool technology in terms of material, shank structure and tool balance. It brings forward that tool material with high property must match with workpiece to get high efficiency and precision in HSM. Three type of shank are introduced and using HSK can get better working performance due to its double-surface positioning and short tapered shank. The paper finally put forward the online balancing test technology which can achieves the actual signal collection of dynamic balance, and make technical analysis as well as processing in high-speed cutting.


Author(s):  
Chao Wang ◽  
Kai Cheng ◽  
Richard Rakowski

This paper presents smart tooling concepts applied to ultra-precision and high speed machining, particularly through the development of smart tool holders, two types of smart cutting tools and a smart spindle for high speed drilling and precision turning purposes respectively. The smart cutting tools presented are force-based devices, which allow measuring the cutting force in real time. By monitoring the cutting force a suitable sensor feedback signal can be captured, which can then be applied for the smart machining. Furthermore, an overview of recent research projects on smart spindle development is provided, demonstrating that signal feedback is very closely correlated to the drilling through a multilayer composite board. Implementation aspects on the proposed smart cutting tool are also explored in the application of hybrid dissimilar material machining.


2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-541-Pr9-546 ◽  
Author(s):  
A. Molinari ◽  
M. Nouari

Alloy Digest ◽  
1982 ◽  
Vol 31 (11) ◽  

Abstract ANACONDA Alloy 360 is a leaded brass and is the alloy most often used for high-speed machining operations; it fills most of the needs for such purposes. Alloy 360 is the standard free-cutting brass and its machinability has become the standard by which all other copper-base alloys are rated. It has medium strength and ductility. Alloy 360 is used for hardware such as gears and pinions where excellent machinability is of prime importance and for all types of automatic high-speed screw-machine products. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-447. Producer or source: Anaconda American Brass Company.


2020 ◽  
Vol 15 ◽  
Author(s):  
Fei Sun ◽  
Guohe Li ◽  
Qi Zhang ◽  
Meng Liu

: Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.


2021 ◽  
Vol 11 (12) ◽  
pp. 5406
Author(s):  
Fei Yin ◽  
Xia Ye ◽  
Hongbing Yao ◽  
Pengyu Wei ◽  
Xumei Wang ◽  
...  

In order to study the spallation phenomenon of titanium alloy under the shock of nanosecond laser, the Neodymium-Yttrium-Aluminum Garnet laser was used to carry out laser shock experiments on the surface of titanium alloy. By observing and measuring the surface morphology of the target material, the forming factors and the changes of the surface morphology under different parameter settings, the forming criteria of the titanium alloy were obtained. The results show that under the single variable method, the change of laser energy can affect the target shape variable, and there is a positive correlation between them. When the thickness was greater than or equal to 0.08 mm, no obvious cracks were found in the targets. Moreover, the number of impact times was the key factor for the target deformation; with the growth of impact times, the target deformation gradually became larger until the crack appeared. The larger the diameter of the spot, the more likely the target was to undergo plastic deformation. The surface of titanium alloy with a thickness of 0.08 mm appeared to rebound under specific laser shock condition. The changes in the back of the target material were observed in real time through a high-speed camera, and the plasma induced by the laser was observed in the process. This study is based on the results of previous studies to obtain the titanium alloy forming criteria, which provides a basis for the setting of laser parameters and the thickness of the target when the nanosecond laser impacts the Ti-6AL-4V target.


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