scholarly journals Theoretical Modeling and Machining Experiments of Cylindrical Microstructure Assisted by Single Point Diamond Turning

Author(s):  
Jingjin Li ◽  
Shijun Ji ◽  
Ji Zhao ◽  
Jianfeng Li ◽  
Handa Dai

Abstract Micro structure requires nanometer-scale surface roughness and micro- or even sub-micron form error accuracy in different applications. Two kinds of modeling theories and methods of micro-feature of rotating body and non-rotating body are studied, and the corresponding tool turning trajectory planning method is put forward. In order to process the designed micro-feature structure successfully and avoid the interference and overcutting between tool and workpiece caused by improper selection of tool parameters, the cutting parameters are analyzed and two error theories are proposed. Then a precision driven turning trajectory planning method is proposed, which can optimize the turning parameters according to the setting error and then optimize the trajectory. The experiments are carried out to verify the proposed theory. The surface roughness and surface accuracy of the features were measured by Talysurf PGI 1240 and KEYENCE vhx900 respectively. The surface roughness and surface accuracy of the cylindrical sine wave groove micro feature surface are 0.1714µm and 1.32µm respectively. The surface roughness and surface accuracy of the cylindrical sinusoidal mesh micro feature surface are 0.1625µm and 1.8µm respectively. The results meet expectations and verify the reliability of the error theory and the trajectory optimization theory.

2007 ◽  
Vol 339 ◽  
pp. 78-83 ◽  
Author(s):  
Jing He Wang ◽  
Shen Dong ◽  
H.X. Wang ◽  
Ming Jun Chen ◽  
Wen Jun Zong ◽  
...  

The method of single point diamond turning is used to machine KDP crystal. A regression analysis is adopted to construct a prediction model for surface roughness and cutting force, which realizes the purposes of pre-machining design, prediction and control of surface roughness and cutting force. The prediction model is utilized to analyze the influences of feed, cutting speed and depth of cut on the surface roughness and cutting force. And the optimal cutting parameters of KDP crystal on such condition are acquired by optimum design. The optimum estimated values of surface roughness and cutting force are 7.369nm and 0.15N, respectively .Using the optimal cutting parameters, the surface roughness Ra, 7.927nm, and cutting force, 0.19N, are obatained.


2014 ◽  
Vol 887-888 ◽  
pp. 1236-1239
Author(s):  
Wang Hao ◽  
Yu Zhang ◽  
Qi Ming Xie

Single-point diamond turning (SPDT) is a machining process making use of a monocrystal diamond tool which possesses nanometric edge sharpness, form reproducibility and wear resistance. The process is capable of producing components with micrometre to submicrometre form accuracy and surface roughness in the nanometre range. The cutting parameters that can make an effect on surface finish and form accuracy of SPDT such as spindle speedfeed ratedepth of cut and so on.


2020 ◽  
Vol 853 ◽  
pp. 18-23
Author(s):  
F.A Oyekunle ◽  
Khaled Abou-El-Hossein

Single-point diamond turning is a technique of ultra-high precision machining that provides excellent quality of surface for mirrors, spherical and aspherical components. In SPDT just like other machining processes, cutting fluid plays an important role in metal removal and tool condition which largely influence the surface of diamond turned surface. In this paper, the surface roughness of diamond turned RSA 431 was studied by investigating the effect of kerosene mist and water as cutting fluids. Higher order response surface of Box-Behnken design was generated using fewer runs than a normal factorial technique. The cutting parameters that were varied for both experiments were depth of cut, feed and, speed. Taylor Hobson PGI Dimension XL surface Profilometer was used to measure the surface roughness after each experimental run. The results show that water when used as cutting fluid during machining, produces better surface roughness than kerosene mist. Predictive models for surface roughness were developed for each experiment. Values from the Mean Absolute Percent Error (MAPE) was used to evaluate and compare the two models to determine the accuracy. RSM also proved to be a better methodology of predicting surface roughness.


2020 ◽  
Vol 305 ◽  
pp. 117-121 ◽  
Author(s):  
Zvikomborero Hweju ◽  
Khaled Abou-El-Hossein

This paper is a presentation of a comparative study of the effect of water and kerosene coolants on surface finish during ultra-high precision diamond turning (UHPDT) of Rapidly Solidified Aluminium alloy (RSA 443). The percentage relative difference between the coolants’ surface roughness values is denoted by the ΔRa parameter. The accuracy of the Response Surface Method (RSM) in predicting surface roughness of water and kerosene-based results is investigated in this paper. The cutting parameters used in the investigation are cutting speed, feed rate and depth of cut. The Taguchi method was used to design the experiment since it provides relatively fewer experimental runs when compared to classical experimental design methods. Mean Absolute Percentage Error (MAPE) values are used to compare RSM’s surface roughness prediction accuracy on both water and kerosene-based results. It is observed that the surface roughness profiles for either coolant are similar, and the use of water coolant yields smoother surface finishes when compared to the use of kerosene. It is also observed that RSM displays better accuracy in predicting water-based surface roughness.


2015 ◽  
Vol 828-829 ◽  
pp. 62-68
Author(s):  
Khaled Abou-El-Hossein

Plastic optical components and lenses produced in mass quantities are usually manufactured using high-precision plastic injection technology. For that, high-precision plastic moulds with aluminium optical inserts made with extremely high dimension accuracy and high optical surface quality are used. Ultra-high precision single-point diamond turning have been successfully used in shaping optical mould inserts from various aluminium grades such as traditional 6061. However, extreme care should be taking when selecting machining parameters in order to produce optically valid surfaces before premature tool wear takes place especially when the machined optical materials has inadequate machining database. The current experimental study looks at the effect of cutting conditions on optical surfaces made from aluminium. The study embarks on helping establish some diamond machining database that helps engineers select the most favourable cutting parameters. The papers reports on the accuracy and surface finish quality received on an optical surface made on mould inserts from a newly developed aluminium alloy. Rapidly solidified aluminium (RSA) grades have been developed recently to address the various problems encountered when being cut by single-point diamond turning operation. The material is characterised by its extremely fine grained microstructure which helps extend the tool life and produce optical surfaces with nanometric surface finish. It is found the RSA grades can be successfully used to replace traditional optical aluminium grades when making optical surfaces. Surface finishes of as low as 10 nanometres and form accuracy of less than one micron can be achieved on RSA.


2019 ◽  
Vol 287 ◽  
pp. 30-34
Author(s):  
Zwelinzima Mkoko ◽  
Khaled Abou-El-Hossein

In the globally competitive environment, surface roughness and finer tolerances are becoming stringent and certainly most critical for optical components. The aim of this study is to determine the effects of diamond turning process parameters on surface finish when diamond turning RSA 443 alloy having high silicon content. This alloy is a new grade of aluminum that has a potential to be used for production of various optical components. The experiments were conducted based on the Box-Behnken design with three diamond-turning parameters varied at three levels. A mathematical regression model was developed for predicting surface roughness. Further, the analysis of variance was used to analyze the influence of cutting parameters and their interaction in machining. The developed prediction model reveals that cutting speed and feed rate are the most dominant diamond turning factors influencing surface roughness.


2012 ◽  
Vol 497 ◽  
pp. 1-5
Author(s):  
Xiao Dan Xie ◽  
Yong Li ◽  
Cam Vinh Duong ◽  
Ahmed Al-Zahrani

Traditionally, single point diamond turning (SPDT) can not process ferreous metals because of acute tool wear. Ultrasonic vibration-assisted cutting(UVC) provides a promising solution for the problem. In this paper, for the aim of directly obtaining mirror surface on die steels, UVC method was used combining with SPDT process. Experiments were carried out on an ultra precision turning machine, cutting parameters and vibration parameters were well-chosen, and two kind of feed rates, two kinds of prevailing die steels were experimented. Mirror surfaces were successfully achieved on face turning, with the best roughness of Ra16.6nm. And the surface roughness, surface texture and tool wear in machining process were discussed.


2012 ◽  
Author(s):  
Honghuai Xu ◽  
Xiangchao Zhang ◽  
Min Xu ◽  
Xufeng Li

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