Characterization of Cutting-Induced Heat Generation in Ultra-Precision Milling of Aluminium Alloy 6061

2013 ◽  
Vol 552 ◽  
pp. 201-206
Author(s):  
Su Juan Wang ◽  
Suet To ◽  
Xin Du Chen
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Heat Generation ◽  
Feed Rate ◽  
Dimensional Accuracy ◽  
Precision Machining ◽  
Machined Surface ◽  
Single Crystal Diamond ◽  
Ultra Precision ◽  
Alloy 6061

The technology of ultra-precision machining with single crystal diamond tool produces advanced components with higher dimensional accuracy and better surface quality. The cutting-induced heat results in high temperature and stress at the chip-tool and tool-workpiece interfaces therefore affects the materials and the cutting tool as well as the surface quality. In the ultra-precision machining of al6061, the cutting-induced heat generates precipitates on the machined surface and those precipitates induce imperfections on the machined surface. This paper uses the time-temperature-precipitation characteristics of aluminum alloy 6061 (al6061) to investigate the effect of feed rate on the cutting-induced heat generation in ultra-precision multi-axis milling process. The effect of feed rate and feed direction on the generation of precipitates and surface roughness in ultra-precision raster milling (UPRM) is studied. Experimental results show that heat generation in horizontal cutting is less than that in vertical cutting and a larger feed rate generates more heat on the machined workpiece. A smaller feed rate produces a better surface finish and under a larger feed rate, scratch marks are produced by the generated precipitates and increase surface roughness.

Effects of the Tool Angles on the Machined Surface Quality of KDP Crystal in Diamond Turning

2007 ◽  
Vol 364-366 ◽  
pp. 297-301 ◽  
Author(s):  
Jing He Wang ◽  
Ming Jun Chen ◽  
Shen Dong ◽  
Shi Qian Wang
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Rake Angle ◽  
Diamond Turning ◽  
Precision Machining ◽  
Machined Surface ◽  
Kdp Crystal ◽  
Factors Affecting ◽  
Ultra Precision ◽  
Back Angle

In the ultra-precision machining of KDP crystal, there are many factors affecting the surface quality[1-3]. The experiments show that the rake angle and back angle of the tool have significant effects on machined surface roughness. Therefore, an efficient way to improve the surface roughness is to select a proper negative rake angle. In this study, the ANSYS static analysis method was employed to analyze the stress field distribution within the whole cutting region. A finite element simulation model was set up to calculate the residual stresses variation with tool’s angles, which can be considered to select optimal rake and back angles in the ultra-precision machining of KDP crystal. Results show that the optimal tool rake angle and back angle are -49° and 7°, respectively. Finally, by using different tool angles to process KDP crystal and utilizing AFM to analyze the surface roughness, it can be found that the measurement results agree well with what are deduced from theoretical calculation.

Experimental Study of the Light Scattering Induced by the Surface Roughness of the Ultraprecision Machined Workpiece

2010 ◽  
Vol 143-144 ◽  
pp. 1091-1096
Author(s):  
Chun Der Cheng ◽  
Hsi Hsun Tsai ◽  
Hui Ping Feng
Keyword(s):  
Surface Roughness ◽  
Light Scattering ◽  
Measurement Technique ◽  
Precision Machining ◽  
Diode Array ◽  
Machined Surface ◽  
Tool Marks ◽  
Scattering Effect ◽  
Photo Diode ◽  
Ultra Precision

An in-situ measurement technique of the surface roughness of ultra-precision machining by optical characteristic effects is fundamental thanks to the probe-less which would avoid the contact damage on the surface. Since the plastic lens molding reprints the roughness from the mould core fabricated by machining, the tool marks induce the poor surface of the plastic lens. By a laser with a short wavelength of He-Ne of 632 nanometers, the machined surface would reflect the input light. Several samples with different surface roughness of the aluminum by varying the feed rate of the ultra-precision machining are used to be measured by the He-Ne laser. The 1 x 16 photo-diode array with the pitch of 2.0 mm is constructed to measure the distribution of the optical scattering effect under the light source of He-Ne laser. Results show that the higher surface roughness gives a more expanse distribution of the light scattering. Besides, the BSDF of the machined surface is proportional to roughness. Using the ratio of the main and side measuring channels of the photo-diode array would give a suitable approach to construct the relationship between the light scattering and surface roughness. Therefore, the laser and the photodiode array would predict well the roughness of the ultra-precision machined surfaces of aluminum. The on-line measurement technique for the roughness by reflected light scattering effect from the ultra-precision machined surface is constructed nice in this study.

Study on Ultra-Precise Machining of CLBO Crystal

2006 ◽  
Vol 304-305 ◽  
pp. 398-402 ◽  
Author(s):  
Xun Lv ◽  
Ju Long Yuan ◽  
Yong Dai ◽  
Jia Jin Zheng ◽  
Zhao Zhong Zhou ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Crystal Surface ◽  
Technical Problem ◽  
Damage Threshold ◽  
Laser Wavelength ◽  
Precision Machining ◽  
Lithium Borate ◽  
Fundamental Laser ◽  
Ultra Precision

Cesium Lithium Borate (CsLiB6O10 or CLBO) is the most effective non-linear crystal which generates ultraviolet harmonics of the Nd:YAG fundamental laser wavelength. In order to enhance the damage threshold, low CLBO surface roughness, by ultra-precision machining, is needed. Because the CLBO crystal has easy hydroscopic reaction and micro scratches in machining, ultra-precise machining of the CLBO crystal is a difficult technical problem. In this paper, the new lapping slurry and polishing slurry are introduced. And the deliquescence degree of CLBO is fallen to lowest. A new working technology is also adopted. After rough polishing, the concentration of ultra-precision polishing slurry is increased properly. So does the ultra-precision polishing speed, and the wiping speed is faster than the deliquescence speed. The CLBO crystal surface roughness can achieve 1nm and keep the surface quality well.

scholarly journals Characterization of the Friction Coefficient of Aluminum Alloy 6061 in Ultra-Precision Machining

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 336 ◽  
Author(s):  
Hailong Wang ◽  
Tao Zhang ◽  
Sujuan Wang ◽  
Suet To
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Surface Generation ◽  
Precision Machining ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Friction Coefficients ◽  
Aluminum Alloy 6061 ◽  
Ultra Precision ◽  
Alloy 6061

Aluminum alloy 6061(Al6061), an Al-Mg-Si alloy, is a precipitation-hardened alloy. The generation of precipitate affects its mechanical properties, and induces a worse surface finish during diamond cutting. The friction coefficients of the tool-chip and tool-workpiece interfaces influence temperature rise, and are therefore important predictors of tool wear and surface integrity during the diamond cutting of Al6061. This study investigated the relationship between precipitate generation and the friction coefficients of Al6061. Groups of experiments were conducted to study the influence of temperature and heating time on the number of precipitates and the friction coefficients. The results show that the generation of AlFeSi particles induces cracks, scratch marks and pits on diamond-machined Al6061 and affects the cutting forces. Moreover, the variation trend of the friction coefficient of Al6061 under different heating conditions agrees well with that of the number of AlFeSi particles. This implies that, during ultra-precision machining of precipitation-hardened alloys, cutting-induced heat causes precipitates to form on the chips and machined surface, changing their material properties. This affects the tool-workpiece and tool–chip contact conditions and the mechanisms of chip formation and surface generation in ultra-precision machining.

scholarly journals Effect of Different Cooling Strategies on Surface Quality and Power Consumption in Finishing End Milling of Stainless Steel 316

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 903
Author(s):  
Adel T. Abbas ◽  
Saqib Anwar ◽  
Elshaimaa Abdelnasser ◽  
Monis Luqman ◽  
Jaber E. Abu Qudeiri ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Power Consumption ◽  
Surface Quality ◽  
Process Parameters ◽  
Feed Rate ◽  
End Milling ◽  
Cutting Speed ◽  
Machined Surface ◽  
Cooling Strategies ◽  
Dry Conditions

In this paper, an experimental investigation into the machinability of AISI 316 alloy during finishing end milling operation under different cooling conditions and with varying process parameters is presented. Three environmental-friendly cooling strategies were utilized, namely, dry, minimal quantity lubrication (MQL) and MQL with nanoparticles (Al2O3), and the variable process parameters were cutting speed and feed rate. Power consumption and surface quality were utilized as the machining responses to characterize the process performance. Surface quality was examined by evaluating the final surface roughness and surface integrity of the machined surface. The results revealed a reduction in power consumption when MQL and MQL + Al2O3 strategies were applied compared to the dry case by averages of 4.7% and 8.6%, respectively. Besides, a considerable reduction in the surface roughness was noticed with average values of 40% and 44% for MQL and MQL + Al2O3 strategies, respectively, when compared to the dry condition. At the same time, the reduction in generated surface roughness obtained by using MQL + Al2O3 condition was marginal (5.9%) compared with using MQL condition. Moreover, the results showed that the improvement obtained in the surface quality when using MQL and MQL + Al2O3 coolants increased at higher cutting speed and feed rate, and thus, higher productivity can be achieved without deteriorating final surface quality, compared to dry conditions. From scanning electron microscope (SEM) analysis, debris, furrows, plastic deformation irregular friction marks, and bores were found in the surface texture when machining under dry conditions. A slight smoother surface with a nano-polishing effect was found in the case of MQL + Al2O3 compared to the MQL and dry cooling strategies. This proves the effectiveness of lubricant with nanoparticles in reducing the friction and thermal damages on the machined surface as the friction marks were still observed when machining with MQL comparable with the case of MQL + Al2O3.

scholarly journals Investigation of Surface Quality for Minor Scale Diameter of Biodegradable Magnesium Alloys during the Turning Process Using a Different Tool Nose Radius

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1174
Author(s):  
Sophal Hai ◽  
Hwa-Chul Jung ◽  
Won-Hyun Shim ◽  
Hyung-Gon Shin
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Turning Process ◽  
Nose Radius ◽  
Machined Surface ◽  
Tool Nose Radius

The main objective of the study is to analyze the various cutting parameters to investigate the surface quality of the minor scale diameter of magnesium alloy in the dry turning process using a different tool nose radius (r). The surface roughness (Ra) was gauged, and micro-images produced by scanning electron microscopy (SEM) were reviewed to evaluate the machined surface topography. The analysis of variance (ANOVA), linear regression model and signal-to-noise (S/N) ratio were applied to investigate and optimize the experimental conditions for surface roughness. The study results imply that the feed rate and tool nose radius significantly affected the surface quality, but the spindle speed did not. The linear regression model is valid to forecast the surface roughness. The cutting parameters for optimum surface quality are a combination of a spindle speed of 710 rpm, a feed rate of 0.052 mm/rev and a tool nose radius of 1.2 mm. The machined surface topography contains the feed marks, micro-voids, material side and material debris, but they become smaller and decrease at a lower feed rate, larger tool nose radius and higher spindle speed. These results show the good surface quality of magnesium alloys in a dry turning process, which could be applied in implant, orthopedic and trauma surgery.

scholarly journals Ultra-High-Speed Magnetic Abrasive Surface Micro-Machining of AISI 304 Cylindrical Bar

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 489 ◽  
Author(s):  
Cheng Yin ◽  
Rui Wang ◽  
Jeong Kim ◽  
Sang Lee ◽  
Sang Mun
Keyword(s):  
Surface Roughness ◽  
Plastic Strain ◽  
High Speed ◽  
Precision Machining ◽  
Plastic Strains ◽  
Abrasive Machining ◽  
Machined Surface ◽  
Aisi 304 ◽  
Ultra High Speed ◽  
Ultra Precision

The ultra-high-speed magnetic abrasive machining (UHSMAM) process is a surface improvement technique, which has been widely used to minimize the surface accuracy and change the precision morphology of difficult-to-machine materials. Surface integrity plays an important role in the machining process, because it is used to evaluate the high stress and the loaded components on the machined surface. It is important to evaluate the plastically deformed layers in ultra-precision machining surface of material. However, the usual plastic strains in the ultra-precision machining surface are significantly difficult to consider. In this paper, an ultra-high-speed magnetic abrasive machining technique is used to improve the surface accuracy and dimensional accuracy of an AISI 304 bars. Additionally, the subsequent recrystallizations technique is used for measuring the plastic strain on machined surface of AISI 304 bars. The purpose of this paper is to evaluate the effects of an UHSMAM process on the plastic strains and the strain energy of the machined surface, and to evaluate the residual strain in the plastic deformation of AISI 304 bars materials by analyzing a plastically deformed layer. The results showed that the plastic strain of the material did not change after machined by an UHSMAM process. Based on the results, an UHSMAM process could significantly improve the surface roughness, micro-diameter, and removal weight of AISI 304 bars effectively. The surface roughness Ra of AISI 304 bars was improved from 0.32 µm to 0.03 µm for 40 s of machining time at 80,000 rpm of workpiece revolution speed.

Ultra-Precision Machining Technology Based on Dynamic Minimum Thickness of Cut for Machined Single Crystal Materials

2011 ◽  
Vol 138-139 ◽  
pp. 1246-1250
Author(s):  
Ji Cai Kuai
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Single Crystal ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Precision Machining ◽  
Minimum Thickness ◽  
Single Crystal Copper ◽  
Ultra Precision ◽  
Relationship Of

The dynamic minimum thickness of cut for the ultra-precision machining surface quality is important influence. Between tool and the workpiece for the friction coefficient were analysised, the relationship of the friction coefficient and the MTC were discussed, and the MTC and its effects on surface roughness were a theoretical analysised and experimental verification with processed single crystal copper and single crystal aluminum by AFM’s diamond tip. The results show: the MTC of single-crystal copper (single crystal aluminum) is 5.2nm (8.2nm) in stable cutting conditions. Further processing single crystal copper (ingle crystal aluminum) with cutting thickness of 5.2nm (8.2nm), and the surface roughness Ra160nm (Ra110nm) is obtained. So the MTC is evolving with the friction coefficient and the force ratio, theoretical MTC tends to be minimal value then before the adhering effect to reach remarkable. Appropriate adjustments cutting parameters, the cutting process can always micro-cutting phase to reach the steady-thin chip, and no plowing phenomenon. So the surface residues highly were reduced and higher surface quality was achieved.

Evaluation of Surface Integrity in Electrochemical Micromachining of A286 Super alloy

2021 ◽  
Author(s):  
Rajkeerthi E ◽  
Hariharan P
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Integrity ◽  
Research Work ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Dissolution Mechanism ◽  
Machined Surface ◽  
Micro Holes ◽  
Super Alloy

Abstract Surface integrity of micro components is a major concern particularly in manufacturing industries as most geometry of the products must meet out necessary surface quality requirements. Advanced machining process like electrochemical micro machining possess the capabilities to machine micro parts with best surface properties exempting them from secondary operations. In this research work, different electrolytes have been employed for producing micro holes in A286 super alloy material to achieve the best surface quality and the measurement of surface roughness and surface integrity to evaluate the machined surface is carried out. The machined micro hole provides detailed information on the geometrical features. A study of parametric analysis meant for controlling surface roughness and improvement of surface integrity has been made to find out the suitable parameters for machining. The suitability of various electrolytes with their dissolution mechanism and the influence of various electrolytes have been thoroughly studied. Among the utilized electrolytes, EG + NaNO3 electrolyte provided the best results in terms of overcut and average surface roughness.

scholarly journals An Investigation To Achieve a Good Surface Integrity in WEDM of Ti-6242 Super Alloy

2021 ◽  
Author(s):  
Sonia Ezeddini ◽  
Wajdi Rajhi ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar ◽  
Sahbi Ben Salem
Keyword(s):  
Surface Roughness ◽  
Pulse Duration ◽  
Surface Integrity ◽  
Surface Finish ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Machined Surface ◽  
Good Surface ◽  
Pulse On Time ◽  
Super Alloy

Abstract Ti-6242 is a super alloy which exhibits the best creep resistance among available titanium alloys and is widely used in the manufacture by WEDM of aircraft engine turbomachinery components. However, the final quality of wire EDMed surface is a great challenge as it is affected by various factors that need optimization for surface integrity and machine efficiency improvement. The aim of this study is to investigate the effect of a set of cutting process parameters such as pulse on time (Ton), servo voltage (U), feed rate (S) and flushing pressure (p) on surface roughness (SR) when machining Ti-6242 super alloy by WEDM process using a brass tool electrode and deionized water as a dielectric fluid. WEDM experiments were conducted, and SR (Ra) measurement was carried out using a 3D optical surface roughness-meter (3D–SurfaScan). As a tool to optimize cutting parameters for SR improvement, Taguchi's signal‐to‐noise ratio (S/N) approach was applied using L9 (3^4) orthogonal array and Lower-The-Better (LTB) criteria. Substantially, the findings from current investigation suggest the application of the values 0.9 µs, 100V, 29 mm/min, and 60 bar for Ton, U, S and p cutting parameters, respectively, for producing a good surface finish quality. Percent contributions of the machining parameters on SR (Ra) assessed based on ANOVA analysis are 62.94%, 20.84%, 11.46% and 4.74% for U, S, Ton and p, respectively. Subsequently, accurate predictive model for SR (Ra) is established based on response surface analysis (RSA). The contour plots for SR (Ra) indicate that when flushing pressure p converges to a critical value (80 bar), a poor-quality surface finish is highly expected with the excessive increase in U and S. Electron microscope scanning (SEM) observations have been performed on machined surface for a wide range of cutting parameters to characterize wire EDMed surface of Ti-6242. SEM micrographs indicate that the machined surface acquires a foamy structure and shows white layer and machining-induced damage that the characteristics are highly dependent on cutting parameters. At high servo-voltage, the decrease in pulse on time Ton and feed rate S results in a large decrease in overall machining-induced surface damage. Moreover, for high servo-voltage and feed rate levels, it has been observed that pulse on time could play a role of controlling the surface microcracks density. In fact, the use of a low pulse duration of cut combined with high servo-voltage and feed rate has been shown to inhibit surface microcracks formation giving the material surface a better resistance to cracking than at high pulse duration.

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