Deep Profiled Slot Grinding on a Nickel-Based Alloy with Electroplated CBN Wheels

2016 ◽  
Vol 1136 ◽  
pp. 3-8 ◽  
Author(s):  
Zhong De Shi ◽  
Amr Elfizy ◽  
Helmi Attia
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Cubic Boron Nitride ◽  
Ground Surface ◽  
Target Material ◽  
Machined Surface ◽  
Turbine Disks ◽  
Nickel Based Alloy ◽  
Grinding Power

A process for grinding deep profiled slots in a nickel-based alloy with electroplated cubic boron nitride (CBN) wheels and straight oil is presented. These slots were prepared by this process for further grinding with electroplated CBN quills to generate the final fir-tree slots in gas turbine disks. Fir-tree slots are usually machined using broaching. The application of broaching, however, is limited in the case of nickel-based powder metal alloys due to short life of broaching tools and the effect on machined surface integrity. Grinding tests were first conducted on rectangular blocks to grind slots without inclinations at a fixed wheel speed vs = 60 m/s to identify the combinations of depths of cut, workspeed, and up/down grinding satisfying the requirements of ground surface quality and material removal rate. Inclined slots were then ground with the identified condition on a block representing a segment of an actual turbine disk to validate the condition. The wheel life was finally tested by grinding all the slots on the actual disk. Grinding power was measured, and the ground surfaces were inspected for any sign of burning. Preset target material removal rate and wheel life were obtained. It was found that electroplated CBN wheels are capable of grinding deep profiled slots on the difficult-to-cut nickel-based alloy.

Grinding-aided electrochemical discharge drilling in the light of electrochemistry

2018 ◽  
Vol 233 (6) ◽  
pp. 1896-1909 ◽  
Author(s):  
VG Ladeesh ◽  
R Manu
Keyword(s):  
Material Removal Rate ◽  
Borosilicate Glass ◽  
Chemical Etching ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Hybrid Technique ◽  
Machined Surface ◽  
Influence Of Process Parameters ◽  
Electrochemical Discharge

The electrically non-conductive materials like glass, ceramics, quartz, etc. are of great interest for many applications in modern industries. Machining them with high quality and at a faster rate is a challenging task. In this study, a novel technique called grinding aided electrochemical discharge drilling (G-ECDD) is demonstrated which uses a hollow diamond core drill as the tool for performing electrochemical discharge machining of borosilicate glass. The new hybrid technique enhances the material removal rate and machining accuracy to several folds by combining the thermal melting action of discharges and grinding action of the abrasive tool. This paper presents the experimental investigation on the material removal rate during G-ECDD of glass while using different electrolytes. An attempt has been made to explore the influence of electrolyte temperature on G-ECDD performance by maintaining the electrolyte at different temperatures. Experiments were conducted using three different electrolytes which include NaOH, KOH, and the mixture of both. The results obtained from this study revealed that an increase in temperature will favor chemical etching as well as electrochemical reaction rate. Also, it was observed that heating the electrolyte leads to an increase in the bubble density and enhances the ion mobility. This causes the formation of gas film at a faster rate and thereby improving the discharge activity. Thus, machining will be done at a faster rate. Better results are obtained while using a mixture of NaOH and KOH. From the microscopic images of the machined surface, it was observed that material removal mechanism in G-ECDD is a combination of grinding action, electrochemical discharges, and chemical etching. Response surface methodology was adopted for studying the influence of process parameters on the performance of G-ECDD. The new technique of grinding aided electrochemical discharge drilling proved its potential to machine borosilicate glass and simultaneously offers good material removal rate, repeatability, and accuracy.

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.

Effect of WEDM process parameters on machinability of Nimonic75 alloy using brass wire

2020 ◽  
Vol 17 (3) ◽  
pp. 389-397
Author(s):  
Harvinder Singh ◽  
Vinod Kumar ◽  
Jatinder Kapoor
Keyword(s):  
Process Parameters ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Content Type ◽  
Response Characteristics ◽  
Nickel Based Alloy ◽  
Pulse On Time ◽  
Pulse Off Time

Purpose This study aims to investigate the influence of process parameters of wire electrical discharge machining (WEDM) of Nimonic75. Nimonic75 is a Nickel-based alloy mostly used in the aerospace industry for its strength at high temperature. Design/methodology/approach One factor at a time (OFAT) approach has been used to perform the experiments. Pulse on time, pulse off time, peak current and servo voltage were chosen as input process parameters. Cutting speed, material removal rate and surface roughness (Ra) were selected as output performance characteristics. Findings Through experimental work, the effect of process parameters on the response characteristics has been found. Results identified the most important parameters to maximize the cutting speed and material removal rate and minimize Ra. Originality/value Very limited research work has been done on WEDM of Nickel-based alloy Nimonic75. Therefore, the aim of this paper to conduct preliminary experimentation for identifying the parameters, which influence the response characteristics such as material removal rate, cutting speed, Ra, etc. during WEDM of Nickel-based alloy (Nimonic75) using OFAT approach and found the machinability of Nimonic75 for further exhaustive experimentation work.

scholarly journals An Experimental Study on the Precision Abrasive Machining Process of Hard and Brittle Materials with Ultraviolet-Resin Bond Diamond Abrasive Tools

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 125 ◽  
Author(s):  
Lei Guo ◽  
Xinrong Zhang ◽  
Shibin Chen ◽  
Jizhuang Hui
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Manufacturing Process ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Abrasive Machining ◽  
Machining Performance ◽  
Machined Surface ◽  
Ultraviolet Curable

Ultraviolet-curable resin was introduced as a bonding agent into the fabrication process of precision abrasive machining tools in this study, aiming to deliver a rapid, flexible, economical, and environment-friendly additive manufacturing process to replace the hot press and sintering process with thermal-curable resin. A laboratory manufacturing process was established to develop an ultraviolet-curable resin bond diamond lapping plate, the machining performance of which on the ceramic workpiece was examined through a series of comparative experiments with slurry-based iron plate lapping. The machined surface roughness and weight loss of the workpieces were periodically recorded to evaluate the surface finish quality and the material removal rate. The promising results in terms of a 12% improvement in surface roughness and 25% reduction in material removal rate were obtained from the ultraviolet-curable resin plate-involved lapping process. A summarized hypothesis was drawn to describe the dynamically-balanced state of the hybrid precision abrasive machining process integrated both the two-body and three-body abrasion mode.

Optimization of Nickel Alloy Turning Considering the Tool in Different Wear Phases

2017 ◽  
Vol 261 ◽  
pp. 243-250
Author(s):  
Wojciech Zębala
Keyword(s):  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Tool Path ◽  
Removal Rate ◽  
Aircraft Engine ◽  
Material Model ◽  
Turning Process ◽  
Engine Part ◽  
Nickel Based Alloy

Paper presents some turning process optimization investigations, concerning modeling of tool wear when turning a difficult-to-cut material like nickel based alloy. The workpiece was an aircraft engine part in the form of disc. The aim of the research was an optimization of the cutting data (feed rate) for the purpose to improve the cutting process (stabilization of the cutting force course along the tool path) and increase the material removal rate (efficiency of the machining). A “force material model”, based on the tool behavior in its different wear phases was established.

Comparative evaluation of powder-mixed and ultrasonic-assisted rough die-sinking electrical discharge machining based on pulse characteristics

2019 ◽  
Vol 233 (14) ◽  
pp. 2515-2530 ◽  
Author(s):  
R Rajeswari ◽  
MS Shunmugam
Keyword(s):  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Graphite Powder ◽  
Machining Process ◽  
Machined Surface ◽  
Ultrasonic Assisted ◽  
Pulse On Time

Electrical discharge machining is used in the machining of complicated shapes in hardened molds and dies. In rough die-sinking stage, attempts are made to enhance material removal rate with a consequential reduction in cycle time. Powder mix and ultrasonic assistance are employed in the electrical discharge machining process to create gap conditions favoring material removal. In the present work, experiments are carried out on hardened D3 die steel using full-factorial design based on three levels of voltage, current and pulse on time. The gap phenomena in graphite powder-mixed and ultrasonic-assisted rough electrical discharge machining are studied using a detailed analysis of pulse shapes and their characteristic trains. Two new parameters, namely, energy expended over a second ( E) and performance factor ( PF) denoting the ratio of energy associated with sparks to total discharge energy, bring out gap conditions effectively. In comparison with the conventional electrical discharge machining for the selected condition, it is seen that the graphite powder mixed in the dielectric enhances the material removal rate by 20.8% with E of 215 J and PF of 0.227, while these values are 179.8 J and 0.076 for ultrasonic-assisted electrical discharge machining with marginal reduction of 3.9%. Cross-sectional images of workpieces also reveal the influence of electrical discharge machining conditions on the machined surface. The proposed approach can be extended to different powder mix and ultrasonic conditions to identify condition favoring higher material removal.

Experimental Investigation of the Material Removal Rate in Grinding of Calcified Plaque by Rotational Atherectomy

2021 ◽  
Author(s):  
Xinxiao Li ◽  
Patrick Chernjavsky ◽  
Katerina Angjeli ◽  
Sola Hoffman ◽  
Sara Frunzi ◽  
...  
Keyword(s):  
Material Removal Rate ◽  
Rotational Speed ◽  
Material Removal ◽  
Removal Rate ◽  
Ground Surface ◽  
Rotational Atherectomy ◽  
Grinding Wheel ◽  
Complication Rates ◽  
Calcified Plaque ◽  
Luminal Area

Abstract Rotational atherectomy (RA) utilizes a high-speed, metal-bonded diamond-abrasive grinding wheel to remove the calcified atherosclerotic plaque inside arteries, restore blood flow, and treat cardiovascular diseases. RA operational guidelines have been clinically investigated to improve clinical outcomes and reduce complication rates, but are still in lack of consensus. Particularly, the effect of the grinding wheel rotational speed on plaque material removal rate (MRR) is unclear. This study experimentally investigates the RA MRR over a range of wheel rotational speeds based on a vascular simulator with a calcified plaque surrogate. The MRR, presented as the luminal area gain, with the increase of the number of grinding passes, was measured at the rotational speed of 120,000, 150,000, and 180,000 rpm. The luminal area was characterized via microscopy and image processing. The ground surface morphology and surface roughness at different rotational speeds were investigated. The results showed that a higher rotational speed led to a higher MRR and a smoother ground surface. This observation is significant for RA clinical guideline improvement.

Experimental Study on Grinding of a Nickel-Based Alloy Using Vitrified CBN Wheels

2011 ◽  
Vol 325 ◽  
pp. 134-139 ◽  
Author(s):  
Zhong De Shi ◽  
Amr Elfizy ◽  
Benoit St-Pierre ◽  
Helmi Attia
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Material Removal ◽  
Removal Rate ◽  
Wheel Wear ◽  
Creep Feed ◽  
Nickel Based Alloy ◽  
Specific Material ◽  
Grinding Power ◽  
Vitrified Cbn

An experimental study is reported on the grinding of a nickel-based alloy using vitrified CBN wheels. This work was motivated by switching the grinding of fir-tree root forms of jet engine blades from creep-feed grinding with conventional abrasive wheels to vitrified CBN wheels. The objective is to explore process limits and practical grinding parameters for judging the switch in terms of overall costs and productivity. Straight surface grinding experiments were conducted with water-based fluid on rectangular blocks at a fixed wheel speed vs = 45 m/s, various depths of cut a = 0.05 - 1.0 mm, and workspeeds vw = 2 - 40 mm/s. Grinding power, forces, surface roughness, and radial wheel wear were measured. Specific material removal rate of 8 mm3/(mm.s) was reached in rough grinding using a wheel dressed for achieving surface roughness Ra = 0.8 µm in finish grinding. It was found that shallow depths of cut combined with fast workspeeds, or less creep-feed modes, are more suitable for achieving high material removal rates with vitrified CBN grinding. Rough grinding is restricted by high grinding temperatures with newly dressed wheels and by chatters with worn wheels.

Investigation into Chemo-Mechanical Fixed Abrasive Polishing of Fused Silica with the Assistance of Ultrasonic Vibration

2012 ◽  
Vol 523-524 ◽  
pp. 155-160 ◽  
Author(s):  
Ya Guo Li ◽  
Yong Bo Wu ◽  
Li Bo Zhou ◽  
Hui Ru Guo ◽  
Jian Guo Cao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Material Removal Rate ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Fused Silica ◽  
Processing Efficiency ◽  
Machined Surface ◽  
Fixed Abrasive

Ultrasonic vibration assisted processing is well known for the improvement in machined surface quality and processing efficiency due to the reduced forces and tribology-generated heating when grinding hard-brittle materials. We transplanted this philosophy to chemo-mechanical fixed abrasive polishing of optical glass, namely fused silica, in an attempt to improve surface roughness and/or material removal rate. Experiments were conducted to elucidate the fundamental characteristics of chemo-mechanical fixed abrasive polishing of fused silica in the presence and absence of ultrasonic vibration on a setup with an in-house built gadget. The experimental results show that ultrasonic vibration assisted chemo-mechanical fixed abrasive polishing can yield increased material removal rate while maintaining the surface roughness of manufactured optics compared to conventional fixed abrasive polishing without ultrasonic vibration. The mechanism of material removal in fixed abrasive polishing was also delved. We found that the glass material is removed through the synergic effects of chemical and mechanical actions between abrasives and glass and the resultant grinding swarf contains ample Si element as well as Ce element, standing in stark contrast to the polisher that contains abundant Ce element and minor Si element.

Experimental Research on Ultrasonic Lapping Al2O3 Engineering Ceramics Using Fixed Oilstones

2006 ◽  
Vol 304-305 ◽  
pp. 340-344 ◽  
Author(s):  
G.F. Gao ◽  
Bo Zhao ◽  
C.S. Liu ◽  
Qing Hua Kong
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Ground Surface ◽  
Average Diameter ◽  
Engineering Ceramic ◽  
Optimal Value ◽  
Ground Surface Roughness ◽  
Experimental Researches

Experimental researches on material removal rate and surface roughness of Al2O3 engineering ceramic guide-pulley lapping were carried out using W20 and W5 fixed oilstones by self-developed ultrasonic lapping tool both with and without ultrasonic assistance. Experimental results show that lapping speed, lapping pressure and grain size produce different effects on the lapped surface roughness and material removal rate. The material removal rate in ultrasonic lapping process is two times as large as that in traditional lapping, and the ground surface roughness is superior to that in common machining method. The material removal rate increases along with the average diameter of grains and the lapping speed both in ultrasonic lapping and traditional lapping. In traditional lapping process the material removal rate becomes bigger along with the lapping force, while in ultrasonic lapping it gets the optimal value with the lapping force 450N. The value of lapped surface roughness increases along with the lapping speed in traditional lapping, on the contrary it decreases contrast to the lapping speed until 250rpm in the ultrasonic lapping. The value of traditionally lapped surface roughness decreases contrast to the lapping force, whereas it achieves the minimum with the lapping force 450N with ultrasonic assistance.

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