Optimizing Computer Controlled-Polishing of Flat Surfaces

Author(s):  
Peiman Mosaddegh ◽  
Rasool Koosha ◽  
Alireza Fadaei Tehrani

The aim of this study is to optimize the Computer Controlled Polishing (CCP) of flat surfaces based on discretization of tool path. First, a new method has been developed to simulate the polishing Process. This method capable of expanding any tool path such as spiral, raster or even random over the surface, meaning that it has the capacity of simulating polishing process under different tool path strategies. Second, a numerical optimization method is applied to optimize the dwell time distribution over the defined tool path. The new method developed in this study was conducted to operate polishing process of a flat lens with 128 mm in diameter and initial surface roughness of 3.975 μm for PV and 987 nm for rms using a 3-axis CNC machine. After two passes of polishing, the final surface roughness reduced to 784 nm for PV and 190 nm for rms which shows around 80 percent reduction in surface roughness for PV and rms.

Author(s):  
Zhen Peng ◽  
Wan-Li Song ◽  
Cui-Li Ye ◽  
Pei Shi ◽  
Seung-Bok Choi

A novel magnetorheological polishing process is devised to polish the internal surface of titanium alloy tubes. Under the magnetic field in polishing area between the internal surface of tube and polishing head, magnetorheological polishing fluid gets stiffened and acts as the polishing tool. In this process, rotation motion of tube and reciprocating linear motion of polishing head are carried out simultaneously resulting in helical motion trajectory of abrasive particles on workpiece surface. The finishing forces during magnetorheological polishing process including normal indentation force and shear force are analyzed and modeled. Based on the proposed model, final surface roughness Ra model is proposed to predict the polishing performance. Experiments are carried out to investigate the effect of polishing time and initial surface roughness Ra on polishing performance. The experimental results are compared with the model results, which are highly consistent. The results show a gradual growth of surface precision with polishing time and an augment of polishing efficiency with increasing initial surface roughness Ra.


Mechanika ◽  
2020 ◽  
Vol 26 (5) ◽  
pp. 457-461
Author(s):  
Nerijus KADZEVIČIUS ◽  
Ieva ŠVAGŽDYTĖ ◽  
Justinas GARGASAS ◽  
Mindaugas JUREVIČIUS ◽  
Artūras KILIKEVIČIUS

There were used the spherical lenses in industry conventional for long time, but new types of lenses were created during innovation processes. One type of lenses is aspherical. Two main parameters describing quality of aspherical lenses are accuracy of the form shape and surface roughness. These parameters can be obtained after last operation – polishing. Technical parameters that give the biggest influence to form shape and surface roughness were investigated in this experiment and optimal technical parameters for polishing process were established. Melted quartz ,,UVFS” was used in this research, investigations were carried out according by full factorial design. Five axis CNC machine Schneider SCPA100 was used for polishing and profilometer Nanoscan 855 was used for measurements. After analysis of results it was found out that speed of rotation and penetration depth are the most important factors in polishing process. For getting the best shape it’s necessary to use the smallest chosen values of speed of rotation and penetration depth, for getting the best surface roughness polishing parameters changing conversely. The smallest value of surface roughness Rz was 0.06 µm, and shape deviation was 2.6 µm. Optimal polishing parameters for the best quality of aspherical lenses was provided.


2011 ◽  
Vol 486 ◽  
pp. 262-265
Author(s):  
Amit Kohli ◽  
Mudit Sood ◽  
Anhad Singh Chawla

The objective of the present work is to simulate surface roughness in Computer Numerical Controlled (CNC) machine by Fuzzy Modeling of AISI 1045 Steel. To develop the fuzzy model; cutting depth, feed rate and speed are taken as input process parameters. The predicted results are compared with reliable set of experimental data for the validation of fuzzy model. Based upon reliable set of experimental data by Response Surface Methodology twenty fuzzy controlled rules using triangular membership function are constructed. By intelligent model based design and control of CNC process parameters, we can enhance the product quality, decrease the product cost and maintain the competitive position of steel.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110118
Author(s):  
Zenan Chu ◽  
Tao Wang ◽  
Qiang He ◽  
Kai Zhao

To solve the problems of low processing efficiency and poor glass surface quality when using rare earth polishing powder to grind super-hard K9 glass. The potential, phase structure, surface morphology, and particle size distribution of the nano-rare earth polishing powder were characterized. Compare the evaluation indexes such as polishing efficiency, surface morphology, and contact angle after the polishing process is changed. The results of the comparative study show that the average surface roughness of the glass after heating ultrasonic polishing process is 0.9064 nm, the polishing rate reaches 0.748 μm/min, the average surface roughness of the glass without heating ultrasonic polishing process is 1.3175 nm, and the polishing rate reaches 0.586 μm/min, the ultrasonic assisted polishing process is superior to the conventional polishing process. The heating ultrasonic method provides experimental basis for precise and rapid processing.


2011 ◽  
Vol 87 ◽  
pp. 82-89
Author(s):  
Potejanasak Potejana ◽  
Chakthong Thongchattu

This research proposes a new application of 3-axis CNC milling machine for polishing the 60 HRC hardness steels. The rotary polishing tools are designed by refer to the end-mill ball nose’s design. The diamond powder are coated in rotary polishing tools by resinoid bonding method and concentrated in 4.4 karat/cm2. The Zig-milling tool paths are used to polish the hardness steel. After polishing, the confocal laser scanning microscope is used to analyze the arithmetic mean surface roughness of the hardness steels. The L12 orthogonal array of the Taguchi’s method is selected to conduct the matrix experiment to determine the optimal polishing process parameters. The diamond grit size and cutting speed of the rotary polishing tools, feed rate and step over of the tool path, the depth of polishing process penetration, and polishing time are used to study. The combination of the optimal level for each factor of the hardness steel polishing process are used to study again in the confirmation experiment. The predicted signal to noise ratio of smaller - the better under optimal condition are calculated by using the data from the experiment. The combination of the optimal level for each factor are used to study again in the confirmation experiment and the result show that polishing time was a dominant parameter for the surface roughness and the next was depth of penetration. The response surface design is then used to build the relationship between the input parameters and output responses. The experimental results show that the integrated approach does indeed find the optimal parameters that result in very good output responses in the rotary polishing tools polished hardness mould steel using CNC milling machine. The mean surface roughness of hardness steel polishing process is improved by the diamond rotary tools with the 3-axis CNC milling machine.


2015 ◽  
Vol 15 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Nilesh Nikam ◽  
Raju S. Pawade

AbstractThis paper presents the application of Response Surface Methodology (RSM) coupled with Teaching Learning Based Optimization Technique (TLBO) for optimizing surface integrity of thin cantilever type Inconel 718 workpiece in ball end milling. The machining and tool related parameters like spindle speed, milling feed, axial depth of cut and tool path orientation are optimized with considerations of multiple response like deflection, surface roughness, and micro hardness of plate. Mathematical relationship between process parameters and deflection, surface roughness and microhardness are found out by using response surface methodology. It is observed that after optimizing the process that at the spindle speed of 2,000 rpm, feed 0.05 mm/tooth/rev, plate thickness of 5.5 mm and 15° workpiece inclination with horizontal tool path gives favorable surface integrity.


2014 ◽  
Vol 575 ◽  
pp. 766-770 ◽  
Author(s):  
Benoit Rosa ◽  
Jean Yves Hascoet ◽  
Pascal Mognol

Laser polishing is a finishing process based on melting material, with the objective of improving surface topography. Some operating parameters must be taken into consideration, such as laser power, feed rate, offset, and overlapping. Moreover, because of its dependence on the primary process, the initial topography has also an impact on the final result. This study describes a quadratic model, conceived to optimize final topography according to the primary process and laser polishing. Based on an experimental matrix, the model takes into account both laser operating parameters and the initial topography, in order to predict polished surfaces and to determine optimal set of parameters. After the phase of experimentation and the creation of the quadratic model, an optimal final topography is introduced, taking into account the initial surface and the laser parameters.


1993 ◽  
Vol 9 (1) ◽  
pp. 27-46 ◽  
Author(s):  
John F. Swigart ◽  
Arthur G. Erdman ◽  
Patrick J. Cain

A new method for quantifying shoe cushioning durability was developed. This method used a computer-controlled, closed-loop materials testing system to subject the shoes to force-time profiles that were indicative of running. The change in the magnitude of the maximum energy absorbed by a shoe and the change in the magnitude of the energy balance of the shoe were quantified after the shoe had been worn running for a given distance. A shoe that changed very little in these quantities had a small energy wear factor and was deemed to have durable cushioning. The test method was roughly validated through comparison of three shoes of different midsole constructions with known relative durabilities. The shoes were tested at four simulated running speeds for energy properties when they were new and after they were run in for 161 km. The relative durabilities of the tested shoes were consistent with expectations based on the shoes' materials and constructions, showing that the new method has promise in predicting shoe cushioning durability, and thus more complete studies of the method may prove useful.


2014 ◽  
Vol 60 (5) ◽  
pp. 200-203
Author(s):  
Andreea Borş ◽  
Cristina Molnar-Varlam ◽  
Melinda Székely

Abstract Objective: The aim of this in vitro study was to evaluate the influence of erosive conditions on the wear resistance of aesthetic direct restorative materials. Methods: Six dental filling materials were tested: two composites (Filtek Z550 and X-tra fil), two compomers (Dyract Extra and Twinky Star) and two glass ionomers (Ketac Molar and Fuji II LC). Twenty disks (10mm×2mm) of each material were prepared (n=120) and kept in artificial saliva at 37˚C for 24 hours. Specimens were cycled in acidic soft drink (Coca-Cola) 5×/day, for 5’, over 30 days. Initial surface roughness ISR (Ra-μm) and final surface roughness FSR were measured using a profilometer. The wear rate was calculated as difference of final minus the initial roughness (ΔSR=FSR-ISR). For statistical analysis t-test and one-way ANOVA test were used by GraphPad Prism version 5.03 statistical software. The level of significance was set at p<0.05. Results: The erosive wear rates (mean±SD, μm) after exposure to acidic beverage were: 0.30±0.03 (Ketac Molar), 0.28±0.04 (Fuji II LC), 0.27±0.00 (Filtek Z550), 0.23±0.01 (X-tra fil), 0.20±0.00 (Twinky Star) and 0.14±0.01 Dyract Extra, respectively. There were significant differences between the tested materials (p<0.05). Conclusions: Dental filling materials had different behaviour under the same erosive condition, however all investigated aesthetic restorative materials showed surface degradation. These findings suggest that erosive wear resistance of tooth coloured restoratives could influence their longevity in intraoral acidic conditions. Acknowledgements: The study was supported by the Internal Research Grant no. 5/30.01.2013 of the University of Medicine and Pharmacy of Tirgu Mureş.


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