scholarly journals Effect of the Lapping Platen Groove Density on the Characteristics of Microabrasive-Based Lapping

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 775
Author(s):  
Taekyung Lee ◽  
Haedo Jeong ◽  
Sangjik Lee ◽  
Doyeon Kim ◽  
Hyoungjae Kim
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Material Removal ◽  
Removal Rate ◽  
High Surface ◽  
Abrasive Particle ◽  
Process Conditions ◽  
Abrasive Particles ◽  
Oil Film ◽  
Process Characteristics

Microabrasive-based lapping is widely used in the manufacturing of single-crystal substrates such as sapphire, SiC, and GaN. Although many studies have been conducted to improve the lapping process characteristics, most of them focused on process conditions or consumables. In this study, the effect of the lapping platen groove density on the lapping characteristics was studied using a sapphire substrate. Groove density was defined as the ratio of groove width to groove pitch, and the displacement of the lapping head was measured to calculate the oil film thickness. It was confirmed that, for groove densities below 0.30, hydroplaning occurs when the oil film thickness increases. When the oil film thickness is larger than the abrasive particle size, the material removal rate is low because the abrasive does not participate in the lapping process. When the oil film was developed, the experimental results showed a high surface roughness and poor flatness of the substrate, as only large abrasive particles participated in the lapping process. Therefore, to improve the lapping characteristics, it is important to reduce the groove density by reducing the groove pitch, which prevents the development of the oil film.

Quartz Wafer Machining Using MCF (Magnetic Compound Fluid) Polishing Liquid Frozen with Liquid Nitrogen

2008 ◽  
Vol 389-390 ◽  
pp. 187-192
Author(s):  
Yong Bo Wu ◽  
Kunio Shimada
Keyword(s):  
Surface Roughness ◽  
Liquid Nitrogen ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Abrasive Particles ◽  
Water Based ◽  
Quartz Wafer ◽  
Polishing Tool

This paper deals with the machining of quartz wafers using an MCF (Magnetic Compound Fluid) polishing liquid, frozen with liquid nitrogen. This type of polishing liquid is composed of water-based MF (Magnetic Fluid), iron powder, abrasive particle and α-cellulose, and consequently reacting to magnetic fields. Experiments of polishing quartz wafers using the MCF method were carried out on a previously developed apparatus. The results show that an MCF polishing liquid, frozen with liquid nitrogen, has greater material removal capability than one that has not been frozen. A frozen MCF polishing liquid containing larger abrasive particles yields a higher material removal rate, however the surface roughness deteriorates. The highest material removal rate and the best surface roughness were obtained when the percentage of water, in the frozen MCF polishing tool, was 34.7%.

High-Throughput Picosecond Laser Machining of Aerospace Nickel Superalloy

2021 ◽  
pp. 095440542110288
Author(s):  
Sundar Marimuthu ◽  
Bethan Smith
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Thermal Damage ◽  
Removal Rate ◽  
Picosecond Laser ◽  
Nickel Superalloy ◽  
Laser Machining ◽  
Process Conditions ◽  
Machining Performance

This manuscript discusses the experimental results on 300 W picosecond laser machining of aerospace-grade nickel superalloy. The effect of the laser’s energetic and beam scanning parameters on the machining performance has been studied in detail. The machining performance has been investigated in terms of surface roughness, sub-surface thermal damage, and material removal rate. At optimal process conditions, a picosecond laser with an average power output of 300 W can be used to achieve a material removal rate (MRR) of ∼140 mm3/min, with thermal damage less than 20 µm. Shorter laser pulse widths increase the material removal rate and reduce the resultant surface roughness. High scanning speeds improve the picosecond laser machining performance. Edge wall taper of ∼10° was observed over all the picosecond laser machined slots. The investigation demonstrates that high-power picosecond lasers can be used for the macro-machining of industrial components at an acceptable speed and quality.

Development of a New Plate Polishing Technique with an Instantaneous Tiny-Grinding Wheel Cluster Based on Magnetorheological Effect

2008 ◽  
Vol 53-54 ◽  
pp. 155-160 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Ai Jun Tang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Abrasive Particles ◽  
Magnetorheological Effect ◽  
Material Removal Model ◽  
Mr Effect ◽  
Removal Model

A new plate polishing technique with an instantaneous tiny-grinding wheel cluster based on the magnetorheological (MR) effect is presented in this paper, and some experiments were conducted to prove its effectiveness and applicability. Under certain experimental condition, the material removal rate was improved by a factor of 20.84% as compared with the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece was not obviously increased. Furthermore, the composite of the MR fluid was optimized to obtain the best polishing performance. On the basis of the experimental results, the material removal model of the new plate polishing technique was presented.

Grinding of Chromium Carbide Coatings Using Electroplated Diamond Wheels

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Zhongde Shi ◽  
Amr Elfizy ◽  
Helmi Attia ◽  
Gilbert Ouellet
Keyword(s):  
Surface Roughness ◽  
Chromium Carbide ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Depth Of Cut ◽  
Process Conditions ◽  
Carbide Coatings ◽  
Grinding Power ◽  
Chromium Carbide Coatings

This paper reports an experimental study on grinding of chromium carbide coatings using electroplated diamond wheels. The work was motivated by machining carbide coatings in gas turbine engine applications. The objective is to explore the process conditions and parameters satisfying the ground surface quality requirements. Surface grinding experiments were conducted with water-based grinding fluid on chromium carbide coated on flat surfaces of aluminum blocks for rough grinding at a fixed wheel speed vs = 30 m/s, and finish grinding at vs = 30, 60 m/s. The effects of depth of cut and workspeed on grinding power, forces, and surface roughness were investigated for each of the wheel speeds. Material removal rate Q = 20 mm3/s for rough grinding at a grinding width b = 101.6 mm was achieved. It was found that the maximum material removal rate achievable in rough grinding was restricted by chatters, which was mainly due to the large grinding width. The specific energy ranged from 27 to 59 J/mm3 under the tested conditions. Surface roughness Ra = 3.5–3.8 μm were obtained for rough grinding, while Ra = 0.6–1.5 μm were achieved for finish grinding. Surface roughness was not sensitive to grinding parameters under the tested conditions, but was strongly dependent on the diamond grain sizes. Imposing axial wheel oscillations to the grinding motions reduced surface roughness by about 60% under the tested condition. It was proved that it is feasible to grind the chromium carbide coating with electroplated diamond wheels.

Optimising the Process Conditions in Ultra-Precision Grinding to Achieve Surface Finish of Optical Quality

2006 ◽  
Vol 304-305 ◽  
pp. 8-13 ◽  
Author(s):  
T. Jin ◽  
D.J. Stephenson
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Material Removal ◽  
Removal Rate ◽  
Optical Quality ◽  
Process Conditions ◽  
Low Alloy Steel ◽  
Optical Surface ◽  
Precision Grinding ◽  
Ultra Precision

Optical surface finish below Ra 10nm can be achieved on a ‘Tetraform C’ grinder of ultra-high stiffness, when grinding a low alloy steel with or without the help of ELID (electrolytic in process dressing). Surface roughness generation modelling has been carried out to predict thepossible surface roughness values. Efforts have been made to transfer the process knowledge to different grinding mode using a rigid 5-axis Edgetek CNC grinder. The effects of material removal rate and grit size and also that of spark out passes on the surface roughness generated have been investigated.

Ultraprecision Machining of Si3N4 Ceramics with Shear-Thickening Polishing

2016 ◽  
Vol 1136 ◽  
pp. 490-493 ◽  
Author(s):  
Min Li ◽  
Bing Hai Lyu ◽  
Ju Long Yuan ◽  
Ping Zhao
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Shear Thickening ◽  
Average Surface Roughness ◽  
Ultraprecision Machining ◽  
Power Law Fluid ◽  
Average Surface ◽  
Fluid Characteristics

Shear-thickening polishing (STP) technology was used on ultraprecision machining of Si3N4 ceramics. The STP slurry with diamond abrasives was prepared for STP process and its rheological property was studied. The polishing performance of Si3N4 ceramics with STP was analyzed. Results show that STP slurry with diamond abrasives exhibits non-Newtonian power-law fluid characteristics with shear-thickening effect. As using STP slurry with abrasive particle size of 0.2 μm, the material removal rate changed from 4.22 to 4.05 μm/h after 60 mins ́ polishing; and decreased from 3.88 to 3.75 μm/h after 120 mins ́ polishing. The average surface roughness reduced from Ra 107.2 to Ra 6.5 nm after 120 mins ́ polishing.

Effect of rotation direction, traverse speed, and abrasive type during the hydroabrasive disintegration of a rotating Ti6Al4V workpiece

2020 ◽  
pp. 095440542097122
Author(s):  
Petr Hlavacek ◽  
Sergej Hloch ◽  
Akash Nag ◽  
Jana Petru ◽  
Miroslav Muller ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Traverse Speed ◽  
Machining Parameters ◽  
Abrasive Particles ◽  
Rotation Direction ◽  
Cartesian Coordinate ◽  
The Right

In this study, a new methodology is considered for determining the rotational senses (clockwise or anti-clockwise) of a workpiece during the hydroabrasive disintegration of rotating samples. The rotational directions are taken with respect to the position of the abrasive jet, that is, keeping it on the right side of the rotating workpiece when viewed from the free end in the cartesian coordinate system. Measurements were carried out for diameter deviation, material removal rate and surface roughness as a response to machining parameters such as traverse speed, workpiece rotation direction and abrasive grain. Final diameter of the workpiece (10.28–14.12 mm), material removal rate (1154–3936 mm3/min) and surface roughness (6.65–25.43 µm) values increase with increasing value of traverse speed (5–25 mm/min) using anti-clockwise rotation with Australian garnet abrasive grains. ANOVA analysis of the responses shows that traverse speed ( p = 0.000) is a statistically significant parameter for predicting all the machining responses. Abrasive type and rotational direction were statistically significant for determining diameter deviation ( p = 0.017, 0.006) and material removal rate ( p = 0.000, 0.000) but insignificant for surface roughness ( p = 0.373, 0.367). Scanning electron microscopy provided information on the surface morphology, depicting the characteristics of the disintegrated surface. Disintegrated features, like peak and valley formations, craters, holes, cutting traces and embedded abrasive particles on the surface were observed.

Study and Optimization of Polymer Lapping on D2 Steel

2010 ◽  
Vol 447-448 ◽  
pp. 26-30
Author(s):  
Yi Ying Zhang ◽  
Ioan D. Marinescu ◽  
Rick VandenBoom
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Regression Models ◽  
Material Removal ◽  
Rotation Speed ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Ductile Materials ◽  
Coated Plate ◽  
D2 Steel

Experimental research on surface roughness and material removal rate of D2 steel lapping is carried out using a polymer plate. The tribological mechanism of lapping for ductile materials is presented and the polymer-based lap plate is described in this study. Thus, an investigation is conducted using ANOVA method to determine the effects of lapping time, lap rotation speed, applied load and abrasive particle size on the lapping process for D2 steel discs with the polymer-coated plate. Regression models are put forward and verified for predicting surface roughness and MRR (material removal rate) as a result of the control variables. An optimal combination of process parameters is given for optimizing the lapping process.

Chemo-Mechanical Grinding for K9 Optical Glass

2014 ◽  
Vol 1002 ◽  
pp. 57-60
Author(s):  
Heng Zhen Dai ◽  
Zhen Hua Jiao ◽  
Bin Wang ◽  
Zhu Ji Jin
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
High Surface ◽  
National Defense ◽  
Mechanical Grinding ◽  
Subsurface Cracks ◽  
Glass Specimen ◽  
Check Experiment

K9 optical glass was widely used in national defense and civilian fields. In this paper, chemo-mechanical grinding (CMG) was applied to process the K9 optical glass. Selecting CeO2, MgO and Fe2O3as CMG abrasives, the corresponding CMG tools were purposely developed for the check experiment. High surface and subsurface qualities on the K9 optical glass specimen were obtained as the polished results by the CeO2-CMG tools. Surface roughness and material removal rate were used to evaluate the grinding performance. The low-abrasive ratio of CeO2-CMG tool was proved as the optimal one, by which the surface roughness Ra reached 0.586nm, and the surface morphology appeared smooth and flat. The angle polishing was applied to detect the subsurface quality and the subsurface cracks were not observed.

scholarly journals Measurement of the Effect of Controlling Parameters on Performance of Abrasive Jet Machine

2020 ◽  
Vol 9 (5) ◽  
pp. 791-795
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Material Removal ◽  
Unique Feature ◽  
Removal Rate ◽  
Particle Temperature ◽  
Abrasive Particle ◽  
Performance Parameters ◽  
Mixing Chamber ◽  
Rotary Mechanism

Abrasive Jet Machine (AJM) widely used for cutting brittle materials. The present study focus on experimental investigation for performance parameters like Material Removal Rate (MRR) and Surface Roughness (SR) with variation in controlling parameters. Here, air pressure, abrasive particle temperature and speed of mixing chamber considered as controlling parameters for measurement of their effects on performance parameters of AJM. Compare to conventional method of AJM, unique feature of heating jacket and rotary mechanism provided in the newly developed AJM for experimental purpose. Experimental results reveal that the MRR and SR gets increased with increase in pressure, temperature and speed of mixing chamber.

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