Ultrahigh Speed Micromachining

2010 ◽  
Author(s):  
Said Jahanmir
Keyword(s):  
Aluminum Alloy ◽  
Feed Rate ◽  
High Speed ◽  
Removal Rate ◽  
Extended Period ◽  
Contact Forces ◽  
Micro Milling ◽  
Dental Ceramics ◽  
Diamond Grit ◽  
High Feed

A new ultrahigh speed micro-spindle has been developed for micromachining that can be used at rotational speeds as high as 500,000 rpm. Since conventional ball bearings or fluid lubricated journal bearings cannot be used at speeds beyond 300,000 rpm for any extended period of time, the new spindle uses a set of journal and thrust foil bearings. The micro-spindle was integrated with a 3-axis micro-milling machine. Cutting experiments were performed on an aluminum alloy at speeds greater than 300,000 rpm using 50 and 300 micron end-mills. The increase in rotational speed to 450,000 rpm in micro-milling of aluminum alloy allowed an increase in feed rate to nearly 800 mm/min (the maximum feed rate available by the positioning stage), thus increasing the material removal rate by more than two orders of magnitude. The dimensional accuracy of several straight cuts made at different feed rates and depths of cut was measured. Theoretical models and research on machining of industrial ceramics have shown that high-speed machining allows for smaller depths of cut by each diamond grit, thus reducing the contact forces and resulting in a reduced possibility of detrimental chipping and subsurface machining damage. Therefore, micro-grinding was performed on dental ceramics to evaluate the feasibility ultrahigh speed machining. In these studies several ceramics used for preparation of dental restorations were cut with diamond tools. The propensity for generation of machining-related damage, such as surface and subsurface microcracks, were greatly reduced by machining at ultrahigh speeds and high feed rates. Micro-machining at such high speeds, and in combination with high feed rates, has never been achieved before.

Effect of Machining Parameters and Wear Mechanism in Milling Mold Steel AISI-P20 and AISI-1050

2014 ◽  
Vol 590 ◽  
pp. 294-298
Author(s):  
Pichai Janmanee ◽  
Somchai Wonthaisong ◽  
Dollathum Araganont
Keyword(s):  
Wear Mechanism ◽  
Feed Rate ◽  
High Speed ◽  
Removal Rate ◽  
Milling Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Aisi P20 ◽  
Steel Aisi ◽  
Quality Surface

In this study, effect of machining parameters and wear mechanism in milling process of mold steel AISI-P20 and AISI-1050, using 10 mm twin flute type end mill diameter. The experimental results found that characteristics of milling surfaces and wear of the mill end were directly influenced by changes of parameters for all test conditions. As a result, the quality of milling surfaces also changed. However, mould steels which had the good quality surface is AISI-1050, with roughnesses of 2.120 μm. Quality milling surfaces were milled by using the most suitable parameter feed rate of 45 mm/min, a spindle speed of 637 rpm and a cut depth level of 3 mm, for both grades. Moreover, material removal rate and duration of the milling process, the milling end mills affect wear of the edge in every bite when the feed rate is low, high speed and level depth of cut at least. It was found that limited wear less will affect the surface roughness (Ra) represents the good quality surface.

Investigation of Surface Roughness and Material Removal Rate for High Speed Micro End Milling on PMMA

2015 ◽  
Vol 1115 ◽  
pp. 12-15
Author(s):  
Nur Atiqah ◽  
Mohammad Yeakub Ali ◽  
Abdul Rahman Mohamed ◽  
Md. Sazzad Hossein Chowdhury
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Feed Rate ◽  
Material Removal ◽  
High Speed ◽  
End Milling ◽  
Removal Rate ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Micro End Milling

Micro end milling is one of the most important micromachining process and widely used for producing miniaturized components with high accuracy and surface finish. This paper present the influence of three micro end milling process parameters; spindle speed, feed rate, and depth of cut on surface roughness (Ra) and material removal rate (MRR). The machining was performed using multi-process micro machine tools (DT-110 Mikrotools Inc., Singapore) with poly methyl methacrylate (PMMA) as the workpiece and tungsten carbide as its tool. To develop the mathematical model for the responses in high speed micro end milling machining, Taguchi design has been used to design the experiment by using the orthogonal array of three levels L18 (21×37). The developed models were used for multiple response optimizations by desirability function approach to obtain minimum Ra and maximum MRR. The optimized values of Ra and MRR were 128.24 nm, and 0.0463 mg/min, respectively obtained at spindle speed of 30000 rpm, feed rate of 2.65 mm/min, and depth of cut of 40 μm. The analysis of variance revealed that spindle speeds are the most influential parameters on Ra. The optimization of MRR is mostly influence by feed rate. Keywords:Micromilling,surfaceroughness,MRR,PMMA

scholarly journals Optimization of Boring Process Parameters in Manufacturing of Polyacetal Bushing using High Speed Steel

2019 ◽  
Vol 130 ◽  
pp. 01031 ◽  
Author(s):  
The Jaya Suteja ◽  
Yon Haryono ◽  
Andri Harianto ◽  
Esti Rinawiyanti
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Feed Rate ◽  
High Speed ◽  
Removal Rate ◽  
High Speed Steel ◽  
Cutting Edge ◽  
Depth Of Cut ◽  
Optimum Result ◽  
Edge Angle

Polyacetal is commonly used as bushing material because of its low coefficient of friction and self lubricant characteristics. The polyacetal is machined by using boring process to produce bushing in certain surface roughness. The objectives of this research are to optimize three independent parameters (depth of cut, feed rate and principal cutting edge angle) of boring process of polyacetal using high speed steel tool to achieve the highest material removal rate and the required surface roughness. Response Surface Methodology is used to investigate the influence of the parameters and optimize the boring process. The research shows that the influence of the boring process parameters on polyacetal is similar compared to on metal. The result reveals that the optimum result is achieved by applying the value of depth of cut, feed rate, and principal cutting edge angle is 2.9 × 10–3 m, 0.229 mm rev–1, and 99.1° respectively. By applying these values, the maximum material rate removal achieved in this research is 1263.4 mm3 s–1 and the surface roughness achieved is 1.57 × 10–6 m.

Fuzzy Comprehensive Evaluation of Aluminum Alloy 7475 High-Speed Milling Parameter Optimization

2011 ◽  
Vol 188 ◽  
pp. 272-276
Author(s):  
Ai Qin Lin ◽  
Min Li Zheng ◽  
Yan Gu ◽  
C.G. Fan
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Removal Rate ◽  
Fuzzy Comprehensive Evaluation ◽  
Cutting Parameters ◽  
Parameters Optimization ◽  
High Speed Milling ◽  
Cutting Parameters Optimization

High-speed cutting is a complexity and uncertainty process .The cutting parameters optimization is ambiguous. In this paper, based on the orthogonal experiment of high-speed milling aluminum alloy 7475, we use fuzzy comprehensive evaluation to optimize the parameters high-speed milling of aluminum alloy 7475 in the indication of surface roughness, cutting force, material removal rate. We have got cutting parameters optimal that is highly processing quality and productivity. Compared optimal results with orthogonal experimental results, we found that the optimal result is reliable. The study shows that fuzzy comprehensive evaluation method can optimize the parameters of high-speed milling of aluminum alloy 7475 accurately. This method has also a good application effect to other materials and great significance to guide actual production.

Experimental Study on Wear-Resistance of Machined Surface in High Speed Milling Aviation Aluminum Alloy

2012 ◽  
Vol 500 ◽  
pp. 117-122
Author(s):  
Xiu Li Fu ◽  
Xiao Qin Wang ◽  
Yong Zhi Pan ◽  
Yang Qiao
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Surface Quality ◽  
Feed Rate ◽  
High Speed ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Machined Surface ◽  
Resistance Performance

The wear-resistance performance of machined surface is an important factor in the evaluation of surface quality and precision in aerospace manufacturing industry. By using high-speed Ring-Block friction and wear machine (MRH-3), the influence of cutting parameters in milling aluminum alloy 7050-T7451 on wear-resistance of machined surface including friction coefficient and wear quantity are experimentally investigated. The wear-resistance is particularly sensitive to cutting speed and feed rate. The friction coefficient has marked drop trends as cutting speed increases. The influence of cutting speed on wear quantity is more complicated and the tendency of wear quantity was ascend in first and descend at last (v>900/min). The results show that the influence of cutting parameters on wear-resistance was also positively correlated with surface roughness and work-hardening of machined surface. The high work-hardening and surface quality had the promoting effecting on wear-resistance. The experiment and analysis results show that the machined surface by high speed cutting and lower feed rate has more superior in surface quality and wear-resistance performance comparing with conventional cutting speed.

Ultra High-Speed Micro-Milling of Aluminum Alloy

2015 ◽  
Author(s):  
Said Jahanmir ◽  
Michael J. Tomaszewski ◽  
Hooshang Heshmat
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Micro Milling ◽  
Burr Formation ◽  
Ultra High Speed ◽  
Cut Quality ◽  
Tool Diameter ◽  
Cutting Speeds

Small precision parts with miniaturized features are increasingly used in components such as sensors, micro-medical devices, micro-fuel cells, and others. Mechanical micromachining processes, e.g., turning, drilling, milling and grinding are often used for fabrication of miniaturized components. The small micro-tools (50 μm to 500 μm diameter) used in micromachining limit the surface speeds achieved at the cutting point, unless the rotational speeds are substantially increased. Although the cutting speeds increase to 240 m/min with larger diameter tools (e.g., 500 μm) when using the highest available spindle speed of 150,000 rpm, the cutting speed with the smaller 50 μm tools is limited to 24 m/min. This low cutting speed at the tool tip is much smaller than the speeds required for efficient cutting. For example, in macro-milling of aluminum alloys the recommended speed is on the order of 60–200 m/min. The use of low cutting speeds limits the production rate, increases tool wear and tendency for burr formation, and limits the degree of dimensional tolerance and precision that can be achieved. The purpose of the present paper is to provide preliminary results that show the feasibility of ultra high-speed micro-milling of an aluminum alloy with respect to surface quality and burr formation. A new ultra high-speed spindle was used for micro-milling of an aluminum alloy with micro-end-mills ranging in diameter from 51 μm to 305 μm. Straight channels were machined to obtain an array of square patterns on the surface. High surface cutting speeds up to 340 m/min were achieved at 350,000 rpm. Inspection of the machined surfaces indicated that edge quality and burr formation tendency are related to the undeformed chip thickness, and therefore the cutting speed and feed rate. The quantity of burrs observed on the cut surfaces was generally small, and therefore, the burr types were not systematically determined. Cutting with the 305 μm tool at a cutting speed of 150 m/min produced an excellent cut quality using a chip thickness of 0.13 μm. However, the cut quality deteriorated as the chip thickness was decreased to 0.06 μm by increasing the cutting speed to 340 mm/min. This result is consistent with published data that show the dependence of bur formation on ratio of chip thickness to tool tip radius. The channel widths were also measured and the width of channels cut with the small diameter tools became larger than the tool diameter at higher speeds. The dependence of the channel widths on rotational speed and the fact that a similar variation was not observed for larger diameter tools, suggested that this phenomena is related to dynamic run-out of the tool tip, which increases the channel width at higher speeds.

scholarly journals Analysis of tool wear and surface roughness in high-speed milling process of aluminum alloy Al6061

2021 ◽  
pp. 71-84
Author(s):  
Nhu-Tung Nguyen ◽  
Dung Hoang Tien ◽  
Nguyen Tien Tung ◽  
Nguyen Duc Luan
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Tool Wear ◽  
Feed Rate ◽  
High Speed ◽  
Cutting Speed ◽  
Milling Process ◽  
Face Milling ◽  
Depth Of Cut ◽  
High Speed Milling

In this study, the influence of cutting parameters and machining time on the tool wear and surface roughness was investigated in high-speed milling process of Al6061 using face carbide inserts. Taguchi experimental matrix (L9) was chosen to design and conduct the experimental research with three input parameters (feed rate, cutting speed, and axial depth of cut). Tool wear (VB) and surface roughness (Ra) after different machining strokes (after 10, 30, and 50 machining strokes) were selected as the output parameters. In almost cases of high-speed face milling process, the most significant factor that influenced on the tool wear was cutting speed (84.94 % after 10 machining strokes, 52.13 % after 30 machining strokes, and 68.58 % after 50 machining strokes), and the most significant factors that influenced on the surface roughness were depth of cut and feed rate (70.54 % after 10 machining strokes, 43.28 % after 30 machining strokes, and 30.97 % after 50 machining strokes for depth of cut. And 22.01 % after 10 machining strokes, 44.39 % after 30 machining strokes, and 66.58 % after 50 machining strokes for feed rate). Linear regression was the most suitable regression of VB and Ra with the determination coefficients (R2) from 88.00 % to 91.99 % for VB, and from 90.24 % to 96.84 % for Ra. These regression models were successfully verified by comparison between predicted and measured results of VB and Ra. Besides, the relationship of VB, Ra, and different machining strokes was also investigated and evaluated. Tool wear, surface roughness models, and their relationship that were found in this study can be used to improve the surface quality and reduce the tool wear in the high-speed face milling of aluminum alloy Al6061

Joint Formation and Mechanical Performance of Friction Self-Piercing Riveted Aluminum Alloy AA7075-T6 Joints

2019 ◽  
Author(s):  
YunWu Ma ◽  
YongBing Li ◽  
ZhongQin Lin
Keyword(s):  
Aluminum Alloy ◽  
Failure Mode ◽  
Feed Rate ◽  
High Speed ◽  
Shear Failure ◽  
Shear Fracture ◽  
Peak Load ◽  
Spindle Speed ◽  
Friction Stir ◽  
Lap Shear

Abstract AA7xxx series aluminum alloys have great potentials in mass saving of vehicle bodies due to pretty high specific strength. However, the use of these high strength materials poses significant challenges to traditional self-piercing riveting (SPR) process. To address this issue, friction self-piercing riveting (F-SPR) was applied to join aluminum alloy AA7075-T6 sheets. F-SPR is realized by feeding a high speed rotating steel rivet to aluminum alloy sheets to form a dissimilar material joint. The effects of spindle speed and rivet feed rate on F-SPR joint cross-section geometry evolution, riveting force and energy input were investigated systematically. It was found that the rivet shank deformation, especially the buckling of the shank tip before penetrating through the top sheet has significant influence on geometry and lap-shear failure mode of the final joint. A medium rivet feed rate combined with a high spindle speed was prone to produce a defect free joint with sound mechanical interlocking. F-SPR joints with the failure mode of rivet shear fracture was observed to have superior lap-shear peak load and energy absorption over the joints with mechanical interlock failure. The optimized F-SPR joint in this study exhibited 67.6% and 13.9% greater lap-shear peak load compared to, respectively, SPR and refill friction stir spot welding joints of the same sheets. This research provides a valuable reference for further understanding the F-SPR process.

The Effects of Cutting Parameters to the Surface Roughness in High Speed Cutting of Micro-Milling Titanium Alloy Ti-6Al-4V

2020 ◽  
Vol 846 ◽  
pp. 133-138
Author(s):  
Gandjar Kiswanto ◽  
Adrian Mandala ◽  
Maulana Azmi ◽  
Tae Jo Ko
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Weight Reduction ◽  
Feed Rate ◽  
High Speed ◽  
Cutting Parameters ◽  
Micro Milling ◽  
Depth Of Cut ◽  
High Speed Cutting ◽  
Micro Scale

Micro-milling offers high flexibility by producing complex 3D micro-scale products. Weight reduction are one of the optimizations of the product that can make it stronger and more efficient nowadays. Titanium are the most commonly used for micro-scale products especially in biomedical industries because of the biocompatibility properties. Titanium alloys offers high strength with low density and high corrosion resistance that is suitable for weight reduction. This study aims to investigate the influence of high speed cutting parameters to the surface roughness in micromilling of titanium alloy Ti-6Al-4V as high speed cutting offers more productivity since producing more cutting length in the same time. experiments are carried out by micromilling process with variations in high speed cutting parameters of spindle speed and feed rate with a constant depth of cut using a carbide cutting tool of with a diameter of 1 mm. The machining results in the form of a 4 mm slot with a depth as the same as depth of cut, which then measures its surface roughness. It was found that higher feed rate that is followed by higher spindle speed will produce better surface roughness.

A Machining Science Approach to Dental Cutting of Glass Ceramics Using an Electric Handpiece and Diamond Burs

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Xiao-Fei Song ◽  
Jian-Hui Peng ◽  
Ling Yin ◽  
Bin Lin
Keyword(s):  
Surface Roughness ◽  
Cutting Forces ◽  
High Speed ◽  
Removal Rate ◽  
Chip Thickness ◽  
Glass Ceramics ◽  
Specific Cutting Energy ◽  
Dental Ceramics ◽  
Cutting Energy ◽  
Specific Material

Dental cutting using handpieces has been the art of dentists in restorative dentistry. This paper reports on the scientific approach of dental cutting of two dental ceramics using a high-speed electric handpiece and coarse diamond burs in simulated clinical conditions. Cutting characteristics (forces, force ratios, specific removal energy, surface roughness, and morphology) of feldspar and leucite glass ceramics were investigated as functions of the specific material removal rate, Qw and the maximum undeformed chip thickness, hmax. The results show that up and down cutting remarkably affected cutting forces, force ratios, and specific cutting energy but did not affect surface roughness and morphology. Down cutting resulted in much lower tangential and normal forces, and specific cutting energy, but higher force ratios. The cutting forces increased with the Qw and hmax while the specific cutting energy decreased with the Qw and hmax. The force ratios and surface roughness showed no correlations with the Qw and hmax. Surface morphology indicates that the machined surfaces contained plastically flowed and brittle fracture regions at any Qw and hmax. Better surface quality was achieved at the lower Qw and the smaller hmax. These results provide fundamental data and a scientific understanding of ceramic cutting using electric dental handpieces in dental practice.

Sign in / Sign up

Export Citation Format

Share Document