scholarly journals Molecular Dynamics Investigation of Residual Stress and Surface Roughness of Cerium under Diamond Cutting

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 386 ◽  
Author(s):  
Yao Li ◽  
Maobing Shuai ◽  
Junjie Zhang ◽  
Haibing Zheng ◽  
Tao Sun ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Residual Stress ◽  
Surface Roughness ◽  
Surface Quality ◽  
Depth Of Cut ◽  
Formation Mechanisms ◽  
Machining Parameters ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Machined Surface Quality

Machined surface quality in terms of residual stress and surface roughness has an important influence on the performance of devices and components. In the present work, we elucidate the formation mechanisms of residual stress and surface roughness of single crystalline cerium under ultraprecision diamond cutting by means of molecular dynamics simulations. Influences of machining parameters, such as the rake angle of a cutting tool, depth of cut, and crystal orientation of the workpiece on the machined surface quality were also investigated. Simulation results revealed that dislocation activity and lattice distortion are the two parallel factors that govern the formation of both residual stress and surface roughness. It was found that both distributions of residual stress and surface roughness of machined surface are significantly affected by machining parameters. The optimum machining parameters for achieving high machined surface quality of cerium by diamond cutting are revealed.

scholarly journals On the Effect of Electron Beam Melted Ti6Al4V Part Orientations during Milling

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1172
Author(s):  
Abdulmajeed Dabwan ◽  
Saqib Anwar ◽  
Ali M. Al-Samhan ◽  
Mustafa M. Nasr
Keyword(s):  
Surface Roughness ◽  
Electron Beam ◽  
Surface Morphology ◽  
Surface Quality ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Radial Depth

The machining of the electron beam melting (EBM) produced parts is a challenging task because, upon machining, different part orientations (EBM layers’ orientations) produce different surface quality even when the same machining parameters are employed. In this paper, the EBM fabricated parts are machined in three possible orientations with regard to the tool feed direction, where the three orientations are “tool movement in a layer plane” (TILP), “tool movement perpendicular to layer planes” (TLP), and “tool movement parallel to layers planes” (TPLP). The influence of the feed rate, radial depth of cut, and cutting speed is studied on surface roughness, cutting force, micro-hardness, microstructure, chip morphology, and surface morphology of Ti6Al4V, while considering the EBM part orientations. It was found that different orientations have different effects on the machined surface during milling. The results show that the EBM parts can achieve good surface quality and surface integrity when milled along the TLP orientation. For instance, surface roughness (Sa) can be improved up to 29% when the milling tool is fed along the TLP orientation compared to the other orientations (TILP and TPLP). Furthermore, surface morphology significantly improves with lower micro-pits, redeposited chips, and feed marks in case of the TLP orientation.

Machined Surface Quality of Pre-Sintered Hardenable PM Steel

2015 ◽  
Vol 659 ◽  
pp. 335-339 ◽  
Author(s):  
Thawatchai Khantisitthiporn ◽  
Monnapas Morakotjinda ◽  
Bhanu Vetayanugul ◽  
Ruangdaj Tongsri
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Texture ◽  
Depth Of Cut ◽  
Hydraulic Pressure ◽  
Average Surface Roughness ◽  
Machined Surface ◽  
Average Surface ◽  
Machined Surface Quality

The benefit of pre-sintered machining is to avoid machining difficulty of sintered parts especially hardenable PM steels. Pre-sintering treatments of green PM part at temperatures lower than the normal sintering temperature of 1120 °C result in green strength improvement high enough for machining. In this study, the influences of various pre-sintering temperatures and several machining conditions on machined surface quality of pre-sintered PM samples were investigated. The pre-sintered samples were machined by a turning process using a carbide cutting insert with varied cutting speeds at a fixed feed rate and depth of cut without cutting lubricant. Chromium alloyed PM steel (Astaloy® CrM) powder samples with (0.5 wt. %C) and without graphite (0 wt. % C) additions mixed with 1 wt. % of zinc stearate were prepared as green parts by cold compaction in a cylindrical die with diameter of 30 mm. Green density was about 7.00 g/cm3 and height of each sample was controlled by hydraulic pressure and powder weight of 80 g/sample. The green samples were treated by pre-sintering treatment before machining testing. Surface quality of each machined sample was evaluated by average surface roughness and surface texture by SEM analysis and the appearance of outlet edge breakout. The experimental results revealed that the pre-sintered samples with graphite addition showed better surface quality in terms of surface roughness and surface texture and small outlet edge breakout appearance. Moreover, at high pre-sintering temperatures of 900 and 1,000°C, the samples showed similar average surface roughness under the same turning conditions. The obtained surface textures were better than those of the samples pre-sintered at 700 and 800°C. The outlet edge breakout could not be found in the graphite-added samples pre-sintering at 1,000°C.

Evaluation of DPI Change Impact on Laser Machined Surface Quality

2014 ◽  
Vol 474 ◽  
pp. 369-374
Author(s):  
Jana Knedlova ◽  
Libuše Sýkorová ◽  
Vladimír Pata ◽  
Martina Malachová
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Laser Micromachining ◽  
Technological Parameters ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Machined Surface Roughness ◽  
Change Impact

The article focuses on the field of PMMA laser micromachining at change of the technological parameters. The aim was to evaluate machined surface roughness at different setting of DPI definition (number of dots paths on square inch). Commercial CO2laser Mercury L-30 by firm LaserPro, USA was used for experimental machining. Ray of laser could be focused on mark diameter d=185 mm.

Fractal-Based Analysis of the Relation Between Surface Finish and Machine Vibration in Milling Operation

2019 ◽  
Vol 19 (01) ◽  
pp. 2050006 ◽  
Author(s):  
Muhammad Owais Qadri ◽  
Hamidreza Namazi
Keyword(s):  
Surface Quality ◽  
Complex Structure ◽  
Vibration Signal ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Machine Vibration ◽  
Milling Operation ◽  
Surface Changes

Analysis of surface quality of machined workpiece is an important issue in machining of materials. For this purpose, scientists analyze how the texture of machined surface changes due to different conditions. Machine vibration is one of the factors that highly affects the surface quality of machined surface. In this research, we analyze the relation between machine vibration and surface quality of machined workpiece. For this purpose, we employ fractal theory and analyze how the complex structure of machined surface changes with the complex structure of machine vibration signal in case of variations of machining parameters, namely, depth of cut, feed rate and spindle speed, in milling operation. Based on the results, variations of surface quality of machined workpiece are related with the variations of complexity of machine vibration signal. The method of analysis employed in this research can be applied to other machining operations in order to find the relation between machine vibration and surface quality of machined workpiece.

Multi Objective Optimization of Cutting Parameters in Machining Cellulose Based Hybrid Composites

2015 ◽  
Vol 761 ◽  
pp. 287-292
Author(s):  
Raja Izamshah ◽  
Zainudin Zuraidah ◽  
Mohd Shahir Kasim ◽  
M. Hadzley ◽  
M. Amran
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Hybrid Composites ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Multi Objective Optimization ◽  
Machining Performance ◽  
Machined Surface ◽  
Multi Objective ◽  
Optimization Of Cutting Parameters

Cellulose based hybrid composites are gaining popularity in the growing green communities. With extensive studies and increasing applications for future advancement, the need for an accurate and reliable guidance in machining this type of composites has increased enormously. Smooth and defect free machined surface are always the ultimate objectives. The present work deals with the study of machining parameters (i.e. spindle speed, feed rate and depth of cut) and their effects on machining performance (i.e. surface roughness and delamination) to establish an optimized setup of machining parameters in achieving multi objective machining performance. Cellulose based hybrid composites consist of jute (a bast fiber) and glass fiber embedded in polyester resins. Response Surface Methodology (RSM) using Box-Behnken Design (BBD) was chosen as the design of experiment approach for this study. Based on that experimental approach, 17 experimental runs were conducted. Mathematical model for each response was developed based on the experimental data. Adequacy of the models were analyzed statistically using Analysis of Variance (ANOVA) in determining the significant input variables and possible interactions. The multi objective optimization was performed through numerical optimization, and the predicted results were validated. The agreement between the experimental and selected solution was found to be strong, between 95% to 96%, thus validating the solution as the optimal machining condition. The findings suggest that feed rate was the main factor affecting surface roughness and delamination .

Effect of SiC Particles on the Machining of Aluminum/SiC Composite

2009 ◽  
Vol 626-627 ◽  
pp. 219-224 ◽  
Author(s):  
Gao Feng Zhang ◽  
Yuan Qiang Tan ◽  
Bi Zhang ◽  
Zhao Hui Deng
Keyword(s):  
Surface Roughness ◽  
Aluminum Matrix ◽  
Volume Ratio ◽  
Damage Mechanism ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Aluminum Metal ◽  
Sic Particles ◽  
Average Grain Size

The objective of this study is to experimentally investigate the effect of reinforced SiC particles on the machining of Aluminum/SiC composite (15% volume ratio of SiC particles with average grain size 15m). Aluminum/SiC composite and aluminum metal were milled by a tungsten carbide endmill in this study. Based on the surface observation and surface roughness inspection, it is found that the machining parameters of Aluminum/SiC composite have optimum values, and that the surface roughness of aluminum/SiC composite is smaller than that of aluminum metal. when feedrate and depth of cut are smaller than limited values, satisfactory surface finish can be attainable, however, as the depth of cut and feedrate increases, the microcracks are first initiated at the interface of SiC particles and aluminum matrix, and then periodically macrocracks are formed on the machined surface, The damage mechanism during the machining of aluminum/SiC are discussed in this paper.

Parametric Study of Machining Effect on Residual Stress and Surface Roughness of Nickel Base Super Alloy UDIMET 720

2008 ◽  
Vol 47-50 ◽  
pp. 13-16 ◽  
Author(s):  
S.V. Joshi ◽  
S. Paul Vizhian ◽  
B.R. Sridhar ◽  
K. Jayaram
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Turbine Engine ◽  
Milling Parameters ◽  
Stress Surface ◽  
Nickel Base ◽  
Engine Components ◽  
Super Alloy

Machining parameters such as speed (v), feed (f) and depth of cut (d) play an important role in determining the residual stress as well as the surface roughness of a material. The material used for the present study is a nickel based super alloy Udiment 720 which finds applications in the manufacture of gas turbine engine components. Residual stress and surface roughness measured on this material showed different magnitudes for different combinations of milling parameters but did not reveal any definite trend. Analytical relationships developed between the magnitudes of residual stress, surface roughness and milling parameters indicated that combined effects of the milling parameters influence both residual stress and surface roughness.

scholarly journals Surface Roughness Analysis of H13 Steel during Electrical Discharge Machining Process Using Cu–TiC Sintered Electrode

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5943
Author(s):  
Arminder Singh Walia ◽  
Vineet Srivastava ◽  
Mayank Garg ◽  
Nalin Somani ◽  
Nitin Kumar Gupta ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Pulse Current ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
H13 Steel ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Semi Empirical

In electrical discharge machining (EDM), the machined surface quality can be affected by the excessive temperature generation during the machining process. To achieve a longer life of the finished part, the machined surface quality plays a key role in maintaining its overall integrity. Surface roughness is an important quality evaluation of a material’s surface that has considerable influence on mechanical performance of the material. Herein, a sintered cermet tooltip with 75% copper and 25% titanium carbide was used as tool electrode for processing H13 steel. The experiments have been performed to investigate the effects of EDM parameters on the machined surface roughness. The findings show that, as the pulse current, pulse length, and pulse interval are increased, the surface roughness tends to rise. The most significant determinant for surface roughness was found to be pulse current. A semi-empirical surface roughness model was created using the characteristics of the EDM technique. Buckingham’s theorem was used to develop a semi-empirical surface roughness prediction model. The semi-empirical model’s predictions were in good agreement with the experimental studies, and the built empirical model based on physical features of the cermet tooltip was tested using dimensional analysis.

scholarly journals Optimization of compressed air assisted-turning-burnishing process for improving machining quality, energy reduction and cost-effectiveness

2020 ◽  
pp. 095440542097666
Author(s):  
Trung-Thanh Nguyen ◽  
Chi-Hieu Le
Keyword(s):  
Surface Roughness ◽  
Energy Consumption ◽  
Surface Hardness ◽  
Compressed Air ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Machining Quality ◽  
Machining Speed ◽  
Burnishing Process

The burnishing process is used to enhance the machining quality via improving the surface finish, surface hardness, wear-resistance, fatigue, and corrosion resistance, and it is mostly used in aerospace, biomedical, and automotive industries to improve reliability and performance of the component. The combined turning and burnishing process is therefore considered as an effective solution to enhance both machining quality and productivity. However, the trade-off analysis between energy consumption, surface characteristics, and production costs has not been well-addressed and investigated. This study presents an optimization of the compressed air assisted-turning-burnishing (CATB) process for aluminum alloy 6061, aimed to decrease the energy consumption as well as surface roughness and to enhance the Vicker hardness of the machined surface. The machining parameters for consideration include the machining speed, feed rate, depth of cut, burnishing force, and the ball diameter. The improved Kriging models were used to construct the relations between machining parameters and the technological response characteristics of the machined surface. The optimal machining parameters were obtained utilizing the desirability approach. The energy based-cost model was developed to assess the effectiveness of the proposed CATB process. The findings showed that the selected optimal outcomes of the depth of cut, burnishing force, diameter, feed rate, and machining speed are 0.66 mm, 196.3 N, 8.0 mm, 0.112 mm/rev, and 110.0 m/min, respectively. The energy consumption and surface roughness are decreased by 20.15% and 65.38%, respectively, while the surface hardness is improved by 30.05%. The production cost is decreased by 17.19% at the optimal solution. Finally, the proposed CATB process shows a great potential to replace the traditional techniques which are used to machine non-ferrous metals.

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