scholarly journals Influence of Mineral Composition in Natural Granite Rocks on Microhardness

2021 ◽  
Vol 49 (1) ◽  
pp. 83-88
Author(s):  
Eszter Kelemen-Cserta ◽  
István Gábor Gyurika
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Elemental Composition ◽  
Mineral Composition ◽  
Machining Parameters ◽  
Granite Rocks

Granites are becoming increasingly popular and, as a result, their areas of use are expanding. In addition to their colour and particle size, the surface roughness of the machined material is becoming an important aspect of their application. In order to create a suitable surface roughness, the type of rocks located on the surface, elemental composition and microhardness of the minerals are important, because knowledge of these characteristics can be used to determine the machining parameters. Microhardness is affected by the atomic percentage values of Si, Al and Na. In addition, for some minerals, a correlation can also be established between the Si, Al and Na components.

scholarly journals Simultaneous optimization of machine and tool parameters for EDM using WC/Co P/M electrode made with micron and nano sized particles

10.30544/582 ◽  
2021 ◽  
Author(s):  
Nadimpalli Sarada Purnima ◽  
Srinivasa Rao Pujari ◽  
Siva Prasad Dora
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Surface Hardness ◽  
Response Characteristic ◽  
Performance Measure ◽  
Influential Factor ◽  
Simultaneous Optimization ◽  
Machining Parameters ◽  
Grey Relational Grade ◽  
Grey Relational

Multi-response characteristic optimization is the most desired aspect of the components produced from electric discharge machining (EDM). Obtaining the optimal combination of parameters for surface roughness (SR) and micro-hardness (MH) is always a challenging task as the machining parameters favourable to one performance measure adversely affects the other. The present paper deals with the simultaneous optimization of SR and MH of D2 alloy steel during EDM with tungsten carbide (WC)/cobalt (Co) P/M electrode by considering electrode and machine tool parameters. Experimental run order was planned with Taguchi’s orthogonal arrays (OA) and in the present investigation, it is based on L18 OA. The analysis of variance (ANOVA) performed for the grey relational grade (GRG) showed that the tool parameter “particle size” (PS) is the most influential factor (61.43%) for simultaneous improvement of performance measures. The P/M electrode made of fine particle size (i.e., at nano level) has improved the process stability and reduced the arcing and short-circuiting results in reduced surface roughness. Simultaneously, the formation of the hard intermetallic phase’s viz., Fe3C, Cr23C6, W2C, Fe6W6C, and Cr2Fe14C on the EDMed surface has increased the surface hardness. The optimal set of parameters was validated through confirmation experiments.

scholarly journals The Optimization of Machining Parameters on Surface Roughness for AISI D3 Steel

2021 ◽  
Vol 1874 (1) ◽  
pp. 012063
Author(s):  
Khair Khalil ◽  
A. Mohd ◽  
C. O. C. Mohamad ◽  
Y. Faizul ◽  
S Zainal Ariffin
Keyword(s):  
Surface Roughness ◽  
Machining Parameters ◽  
Aisi D3 Steel

scholarly journals An Investigation of the High-Frequency Ultrasonic Vibration-Assisted Cutting of Steel Optical Moulds

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 460
Author(s):  
Canbin Zhang ◽  
Chifai Cheung ◽  
Benjamin Bulla ◽  
Chenyang Zhao
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
High Frequency ◽  
Optical Glass ◽  
Contact Point ◽  
Cutting Speed ◽  
Optical Quality ◽  
Machining Parameters ◽  
Nose Radius ◽  
Cutting Geometry

Ultrasonic vibration-assisted cutting (UVAC) has been regarded as a promising technology to machine difficult-to-machine materials such as tungsten carbide, optical glass, and hardened steel in order to achieve superfinished surfaces. To increase vibration stability to achieve optical surface quality of a workpiece, a high-frequency ultrasonic vibration-assisted cutting system with a vibration frequency of about 104 kHz is used to machine spherical optical steel moulds. A series of experiments are conducted to investigate the effect of machining parameters on the surface roughness of the workpiece including nominal cutting speed, feed rate, tool nose radius, vibration amplitude, and cutting geometry. This research takes into account the effects of the constantly changing contact point on the tool edge with the workpiece induced by the cutting geometry when machining a spherical steel mould. The surface morphology and surface roughness at different regions on the machined mould, with slope degrees (SDs) of 0°, 5°, 10°, and 15°, were measured and analysed. The experimental results show that the arithmetic roughness Sa of the workpiece increases gradually with increasing slope degree. By using optimised cutting parameters, a constant surface roughness Sa of 3 nm to 4 nm at different slope degrees was achieved by the applied high-frequency UVAC technique. This study provides guidance for ultra-precision machining of steel moulds with great variation in slope degree in the pursuit of optical quality on the whole surface.

In Situ: A Novel Approach for the Production of Micro Holes

2010 ◽  
Vol 126-128 ◽  
pp. 885-890
Author(s):  
K.P. Somashekhar ◽  
N. Ramachandran ◽  
Jose Mathew
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Feed Rate ◽  
Machining Parameters ◽  
Average Roughness ◽  
Arithmetic Average ◽  
Quantitative Correlation ◽  
Good Surface ◽  
Novel Approach ◽  
Micro Holes

This work is on the preparation of microelectrodes for μ-EDM operation using μ-WEDG process. Electrodes of Ø500 μm are fabricated with various discharge energy machining conditions. Effects of gap voltage, capacitance & feed rate on the surface finish of the electrodes and overcut of the thus produced micro holes are investigated. The profile of microelectrodes is measured using surface roughness tester with 2μm stylus interfaced with SURFPAK software. The study demonstrated that for brass electrodes an arithmetic average roughness value as low as 1.7μm and an overcut of 3 µm could be achieved. The significant machining parameters are found using ANOVA. Surface of the produced microelectrodes are examined using Scanning Electron Microscope. μ-WEDG process parameters could be adjusted to achieve good surface integrity on microelectrodes. Experimental results showed that the surface roughness of microelectrodes depended primarily on feed rate of the electrode. The observations showed the clear and quantitative correlation existing between the micrometer level surface quality and process parameters. The resulting microelectrodes are found to be of exceptionally high quality and could be used for μ- EDM operation on different types of work materials.

Comparative Analysis between Conventional and Dry Turning

2017 ◽  
Vol 261 ◽  
pp. 267-274
Author(s):  
Pantelis N. Botsaris ◽  
Chaido Kyritsi ◽  
Dimitris Iliadis
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Cutting Tool ◽  
Spindle Motor ◽  
Air Cooling ◽  
Machining Parameters ◽  
Turning Process ◽  
Dry Cutting ◽  
Cold Air ◽  
Cooling And Lubrication

In this paper, there is an attempt to monitor and evaluate machining parameters when turning 34CrNiMo6 material under different cooling and lubrication conditions. The machining parameters concerned are temperature of the cutting tool and the workpiece, level of vibrations of the cutting tool, surface roughness of the workpiece, noise levels of the turning process and current drawn by the main spindle motor. Four different experimental machining scenarios were completed, specifically: conventional wet turning process, dry cutting and two additional modes employing cooling by cold air. Experimental data were acquired and recorded by an optimally designed network of sensors. Experimental data were statistically analyzed in order to reach conclusions. According to the research that has been done, although, overall, minimum cutting tool and workpiece temperatures were observed under wet machining, cold air cooling is capable of achieving comparable cooling results to wet machining. The lowest values of surface roughness were achieved by wet machining, whereas the lowest level of cutting tool vibrations were observed under cold air cooling.

Prediction of Surface Roughness in Compressed Air Jet Assisted High Speed End Milling of Silicon Using Diamond Coated Tools

2012 ◽  
Vol 576 ◽  
pp. 41-45
Author(s):  
A.K.M. Nurul Amin ◽  
M.A. Mahmud ◽  
M.D. Arif
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Surface Finish ◽  
High Speed ◽  
End Milling ◽  
Silicon Wafers ◽  
Compressed Air ◽  
Machining Parameters ◽  
High Quality ◽  
Ductile Mode

The majority of semiconductor devices are made up of silicon wafers. Manufacturing of high-quality silicon wafers includes numerous machining processes, including end milling. In order to end mill silicon to a nano-meteric surface finish, it is crucial to determine the effect of machining parameters, which influence the machining transition from brittle to ductile mode. Thus, this paper presents a novel experimental technique to study the effects of machining parameters in high speed end milling of silicon. The application of compressed air, in order to blow away the chips formed, is also investigated. The machining parameters’ ranges which facilitate the transition from brittle to ductile mode cutting as well as enable the attainment of high quality surface finish and integrity are identified. Mathematical model of the response parameter, the average surface roughness (Ra) is subsequently developed using RSM in terms of the machining parameters. The model was determined, by Analysis of Variance (ANOVA), to have a confidence level of 95%. The experimental results show that the developed mathematical model can effectively describe the performance indicators within the controlled limits of the factors that are being considered.

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