Theoretical Modeling and Experimental Verification of Surface Roughness in Abrasive Jet Finishing

2009 ◽  
Vol 16-19 ◽  
pp. 450-455
Author(s):  
Chang He Li ◽  
Zhan Rui Liu ◽  
Guang Qi Cai

Based on the modeling and experiments concerning the surface roughness in abrasive jet finishing with grinding wheel as restraint, the effect of abrasive size, abrasive fluid concentration, machining cycle, wheel velocity and carrier fluid on machined surface quality was investigated. Surface grinder M7120 was employed in a jet machining experiment conducted with W18Cr4V and 40Cr materials, profilometer TALYSURF was used to measure the micro geometrical parameters after machining, and SEM was used to observe surface micro-morphology. Experimental results show that with W7 Al2O3 powder at the mass fraction of 10% and antirust lubricating liquid being adopted in jet machining for 20 to 30 cycles, not only high surface shape precision can be kept or obtained, but also defect-free machined surface with the roughness of Ra0.15~1.6µm can be obtained with high efficiency. Experimental observation and experimental results proved that the experimental results agree well with a mechanism-based machining model.

2010 ◽  
Vol 44-47 ◽  
pp. 975-979
Author(s):  
Ya Li Hou ◽  
Chang He Li ◽  
Yu Cheng Ding

Based on the modeling and experiments concerning the surface roughness in abrasive jet finishing with grinding wheel as restraint, the effect of abrasive size, abrasive fluid concentration, machining cycles, wheel velocity and carrier fluid on machined surface quality was investigated. Surface grinder M7120 was employed in a jet machining experiment conducted with W18Cr4V and 40Cr materials, profilometer TALYSURF was used to measure the micro geometrical parameters after machining, and SEM was used to observe surface micro-morphology. Experimental results show that with W7 Al2O3 powder at the mass fraction of 10% and antirust lubricating liquid being adopted in jet machining for 20 to 30 cycles, not only high surface shape precision can be kept or obtained, but also defect-free machined surface with the roughness of Ra0.15~1.6µm can be obtained with high efficiency. Experimental observation and experimental results proved that the experimental results agree well with a mechanism-based machining model.


2009 ◽  
Vol 69-70 ◽  
pp. 49-53
Author(s):  
Shao Hui Yin ◽  
Hitoshi Ohmori ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Feng Jun Chen ◽  
...  

ELID (electrolytic in-process dressing) grinding was proposed by one of the authors for automatic dressing the grinding wheel while performing grinding for a long time. It offers a high effective way and has been widely used for grinding hard and brittle optical materials. However, those surfaces produced by fixed abrasive grinding are characterized by considerable sub-surface damage, micro-crack. Magneto-rheological finishing (MRF) is a novel precision finishing process for deterministic form correction and polishing of optical materials by utilizing magneto-rheological fluid. In this paper, an ultra-precision synergistic finishing process integrated MRF and ELID grinding is proposed for shorten total finishing time and improve finishing quality. A lot of nano-precision experiments have been carried out to grind and finish some optical materials such as silicon, silicon carbide, etc. ELID grinding is employed to obtain high efficiency and high surface quality, and then, MRF is employed to improve further surface roughness and form accuracy. In general, form accuracy of ~ λ/20 nm peak-to-valley (P-V) and surface roughness less than 10 Angstrom are produced in high efficiency.


2006 ◽  
Vol 532-533 ◽  
pp. 61-64 ◽  
Author(s):  
Chang He Li ◽  
Guang Qi Cai ◽  
Shi Chao Xiu

The abrasive jet finishing process with wheel as restraint is a kind of compound precision finishing process that combined grinding with abrasive jet machining, in which inject slurry of abrasive and liquid solvent to grinding zone between grinding wheel and work surface under no radial feed condition when workpiece grinding were accomplished. The abrasive particles are driven and energized by the rotating grinding wheel and liquid hydrodynamic pressure and increased slurry speed between grinding wheel and work surface to achieve micro removal machining. The micro removal machining with grinding wheel as restraint, not only to attain higher surface form accuracy but also to can acquire efficiently defect-free finishing surface with Ra0.15~ 1.6μm and finally achieve high efficiency, high precision and low roughness values, furthermore, integrating grinding process and abrasive jet process into one features. In the paper, surface topography and tribological characteristics finished by abrasive jet with grinding wheel as restraint were analyzed. Experiments were performed with plane grinder M7120 and workpiece material Q235A. The machined surface morphology was studied using SEM and the microscope and microcosmic geometry parameters were measured with TALSURF5 instrument. The experimental results show that microcosmic geometry parameter values were diminished comparing with ground surface. The tribological characteristics of finished surface were also investigated with pin on disk wear tester of MG-2000. The experimental results show that the friction coefficient and wear amounts of finishing machining surface were obviously decreased comparing with ground surface. As a result, life and precision consistency of finished workpiece were improved.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Woo Jin Jeong ◽  
Jong Ik Lee ◽  
Hee Jung Kwak ◽  
Jae Min Jeon ◽  
Dong Yeol Shin ◽  
...  

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.


2013 ◽  
Vol 332 ◽  
pp. 270-275 ◽  
Author(s):  
Tadeusz Mikolajczyk

Paper shows system to surface shape and quality control in machining using industrial robot. To surface control videooptical methods were used. Surface shape was controlled using the special reverse engineering system. To surface roughness measure machined surface reflectivity method was used. Used own constructions non contact system was equipped with red laser light and USB camera. Wrist of robot was equipped with grinding tool. In paper shows some algorithms of presented processes. Shown too examples of experiments results in surface roughness measure in start end of grinding process. First trials of presented system shows possibility to build smart machining system for finishing of surface with unknown shape.


2019 ◽  
Vol 3 (2) ◽  
pp. 131-141
Author(s):  
Evan Hanks ◽  
Anthony Palazotto ◽  
David Liu

Purpose Experimental research was conducted on the effects of surface roughness on ultrasonic non-destructive testing of electron beam melted (EBM) additively manufactured Ti-6Al-4V. Additive manufacturing (AM) is a developing technology with many potential benefits, but certain challenges posed by its use require further research before AM parts are viable for widespread use in the aviation industry. Possible applications of this new technology include aircraft battle damage repair (ABDR), small batch manufacturing to fill supply gaps and replacement for obsolete parts. This paper aims to assess the effectiveness of ultrasonic inspection in detecting manufactured flaws in EBM-manufactured Ti-6Al-4V. Additively manufactured EBM products have a high surface roughness in “as-manufactured” condition which is an artifact of the manufacturing process. The surface roughness is known to affect the results of ultrasonic inspections. Experimental data from this research demonstrate the ability of ultrasonic inspections to identify imbedded flaws as small as 0.51 mm at frequencies of 2.25, 5 and 10 MHz through a machined surface. Detection of flaws in higher surface roughness samples was increased at a frequency of 10 MHz opposed to both lower frequencies tested. Design/methodology/approach The approach is to incorporate ultrasonic waves to identify flaws in an additive manufactured specimen Findings A wave frequency of 10 MHz gave good results in finding flaws even with surface roughness present. Originality/value To the best of the authors’ knowledge, this was the first attempt that was able to identify small flaws using ultrasonic sound waves in which surface roughness was present.


Author(s):  
Van Nga Tran Thi ◽  
Khanh Nguyen Lam ◽  
Cuong Nguyen Van

In machining processes, grinding is often chosen as the final machining method. Grinding is often chosen as the final machining method. This process has many advantages such as high precision and low surface roughness. It depends on many parameters including grinding parameters, dressing parameters and lubrication conditions. In grinding, the surface roughness of a workpiece has a significant influence on quality of the part. This paper presents a study of the grinding surface roughness predictions of workpieces. Based on the previous studies, the study built a relationship between the abrasive grain tip radius and the Standard marking systems of the grinding wheel for conventional and superabrasive grinding wheels (diamond and CBN abrasive). Based on this, the grinding surface roughness was predicted. The proposed model was verified by comparing the predicted and experimental results. Appling the research results, the surface roughness when grinding three types of steel D3, A295M and SAE 420 with Al2O3 and CBN grinding wheels were predicted. The predicted surface roughness values were close to the experimental values, the average deviation between predictive results and experimental results is 15.11 % for the use of Al2O3 grinding wheels and 24.29 % for the case of using CBN grinding wheels. The results of the comparison between the predicted model and the experiment show that the method of surface roughness presented in this study can be used to predict surface roughness in each specific case. The proposed model was verified by comparing the predicted and measured results of surface hardness. This model can be used to predict the surface hardness when surface grinding


2005 ◽  
Vol 291-292 ◽  
pp. 207-212 ◽  
Author(s):  
Hitoshi Ohmori ◽  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
...  

Metal bonded diamond grinding wheels are widely used in the grinding process, especial in ELID grinding. However, truing is difficult owing to the high toughness of metal bond materials and high hardness of diamond abrasives. To realize high precision and high-efficiency truing, we propose a new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing in this paper. The process principle and fundamental experimental results are introduced, and the truing performance is discussed. Research results show that the proposed new method is effective for truing metal bonded diamond grinding wheels.


2014 ◽  
Vol 800-801 ◽  
pp. 607-612 ◽  
Author(s):  
Cheng Zhe Jin ◽  
Rui Fang

High speed turn-milling has superiority on the productivity and the quality of work pieces, and is more suitable to machine micro-shaft parts and desirable miniature parts based on the turn-milling technology. In this papers adopting orthogonal experiment method cutting experiments of orthogonal turn-milling Aluminum alloy have been done. The relation between turn-milling regimes (cutter rotate speed, axial feed, feed per tooth etc.) and machined surface roughness has been ascertained. Finally, primary and secondary order of cutting regimes impacting surface roughness has more been confirmed through orthogonal experiments variance analysis, the rotate speed of cutter (cutting speed) influence greatly on surface roughness. Through 2-dimension surface topography diagram and 3-dimension surface topography of processed surface, it can be seen that high speed turn-milling processing technology can process micro miniature component of high surface quality, and features excellent development prospect and application value.


2011 ◽  
Vol 299-300 ◽  
pp. 1060-1063 ◽  
Author(s):  
Y.X. Yao ◽  
Jin Guang Du ◽  
Jian Guang Li ◽  
H. Zhao

Mill-grinding experiments were carried out on SiCp/Al to investigate effects of mill-grinding parameters and grinding wheel parameters on machined surface roughness in this paper. The machined surface topography was also analyzed. Experimental results show that surface roughness increases with increasing feed rate and the depth of the mill-grinding. The effect of mill-grinding speed on surface roughness is low. The machined surface reveals many defects. The fine grit diamond grinding wheel can reduce the surface roughness and decrease the machined surface defect. Compared to the vitrified bonded diamond and electroplated diamond grinding wheels used in the experiment, the resin-based diamond grinding wheel produces a better surface.


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