Modeling and Predicting Roughness of the Abrasive Jet Finishing with Grinding Wheel as Restraint

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 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.


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 ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 304
Author(s):  
Xiao-lan Xiao ◽  
Guang-xian Li ◽  
Hai-juan Mei ◽  
Qiu-sheng Yan ◽  
Hua-tay Lin ◽  
...  

In this study, a novel finishing method, entitled clustered magnetorheological finish (CMRF), was proposed to improve surface finish of the silicon nitride ( Si 3 N 4 ) balls with ultra fine precision. The effects of different polishing parameters including rotation speeds, eccentricities and the machining gaps on surface finish of Si 3 N 4 balls were investigated by analyzing the roughness, sphericity and the micro morphology of the machined surface. The experimental results showed that the polishing parameters significantly influenced the surface finish. The best surface finish was obtained by using the polishing parameters: the machining gap of 0.8 mm, the eccentricity of 10 mm and the rotation ratio of 3/4. To further investigate the influence of the polishing parameters on the surface finish, an analytical model was also developed to analyze the kinematics of the ceramic ball during CMRF process. The resulting surface finish, as a function of different polishing parameters employed, was evaluated by analyzing the visualized finishing trace and the distribution of the contact points. The simulative results showed that the distribution and trace of the contact points changed with different polishing parameters, which was in accordance with the results of experiments.


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.


2007 ◽  
Vol 359-360 ◽  
pp. 244-248 ◽  
Author(s):  
Chang He Li ◽  
Shi Chao Xiu ◽  
Guang Qi Cai

The surface integrity finished by abrasive jet with grinding wheel as restraint was experimentally investigated. Experiments were performed with plane grinder M7120 equiped with abrasive jet finishing device and harded workpiece material 45 steel which was ground with the surface roughness values of Ra=0.6μm.The machined surface morphology was studied using Scanning Electron Microscope (SEM) and microscope and microcosmic geometry parameters were measured with TALYSURF5 instrument. The surface hardness for ground and finished surface was measured with HVS-1000 instrument and the phase structure was analyzed by X-ray energy dispersive spectram and residual stresses were measured by PW3208 X-ray diffraction. The Results show that longitudinal geometry parameter values were diminished and ripple was obviously improved comparing with ground surface. Furthermore, the finished surface has condensible residual stresses and high surface hardness comparability compared to grinding machining surface. As a result, life and precision consistency of finished workpiece were improved.


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.


2009 ◽  
Vol 407-408 ◽  
pp. 555-559
Author(s):  
Chang He Li ◽  
Ya Li Hou ◽  
Guo Yu Liu ◽  
Bing Heng Lu

The process technique on abrasive jet finishing process with wheel as restrain was investigated by experimental. The effects of different particle size, abrasive concentration, machining cycles, the velocity of grinding wheel and medium type on surface quality were analyzed. Experiments were performed with plane grinder M7120 and workpiece material 40Cr steel. The machined surface morphology was studied using Scanning Electron Microscope (SEM) and microscope and microcosmic geometry parameters were measured with TALYSYURF5 instrument respectively. The experimental results under percentage 10 abrasive concentration, Al2O3 abrasive particle with W7 size and machining 20~30 circles showing the novelty process method, not only to attain higher surface form accuracy, to diminish grinding defects such as severely deformation, surface layer pollution and ground burnout, but also to can acquire efficiently free defects finishing surface with Ra0.15~1.6µm and finally achieve high efficiency, high precision and low roughness values. Furthermore, integrate grinding process and abrasive jet finishing process into one feature.


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.


2021 ◽  
Vol 1047 ◽  
pp. 62-67
Author(s):  
Shen Wang ◽  
Le Tong ◽  
Guang Jun Chen ◽  
Mao Xun Wang ◽  
Bin Dai ◽  
...  

7075 aluminum alloy is widely used due to its great performance, especially in aerospace area. In this paper, ultrasonic-assisted grinding technology is used to process 7075 aluminum alloy. The data is obtained through experiments, and the surface roughness and morphology of ultrasonic assisted grinding and conventional grinding under different spindle speeds, feed rates, and amplitudes are analyzed. Research has found that the increase in spindle speed and amplitude will improve the quality of the machined surface and reduce the surface roughness by 82.1% and 36%. However, with the increase of feed rate, the surface quality decreased significantly, and the surface roughness increased by 55.6%. The surface micro-morphology of the machined workpiece is observed, and the effects of different processing parameters on the surface micro-morphology are obtained.


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