An Acoustic Emission-Based Method for Determining Contact Between a Tool and Workpiece at the Microscale

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Keith A. Bourne ◽  
Martin B. G. Jun ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
Surface Roughness ◽  
Acoustic Emission ◽  
Machine Tool ◽  
Detection System ◽  
Surface Characteristics ◽  
Tool Geometry ◽  
Detection Error ◽  
Workpiece Surface ◽  
Part Surface ◽  
Overshoot And Undershoot

An acoustic emission-based touch-off detection system has been developed to determine contact between a rotating microtool and a workpiece surface with micron-level accuracy. The system has been implemented on an existing three-axis microscale machine tool. The system has been tested with microendmills as small as 50μm in diameter and microdrills as small as 254μm in diameter. The accuracy of the system has been found to depend on tool geometry and workpiece surface characteristics and is generally on the order of 1μm. An analytical model has been constructed to predict touch-off detection error. The calibrated model has been shown to predict surface overshoot and undershoot trends quite well. Simulations have shown that touch-off error is dominated by part surface roughness.

An Acoustic Emission-Based Method for Determining Relative Orientation Between a Tool and Workpiece at the Micro-Scale

2006 ◽  
Author(s):  
Keith A. Bourne ◽  
Martin B. G. Jun ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
Acoustic Emission ◽  
Detection System ◽  
Surface Characteristics ◽  
Relative Orientation ◽  
Tool Geometry ◽  
Workpiece Surface ◽  
Micro Scale ◽  
Part Surface ◽  
Micro Tool ◽  
Overshoot And Undershoot

An acoustic emission-based touch-off detection system has been developed to determine the relative orientation between a rotating micro-tool and a workpiece surface with micron-level accuracy. The system has been implemented on an existing 3-axis micro-scale machine tool (mMT). The system has been tested with micro-endmills as small as 50 μm in diameter and micro-drills as small as 254 μm in diameter. The accuracy of the system has been found to depend on tool geometry and workpiece surface characteristics and is generally on the order of one micron. An analytical model has been constructed to predict touch-off detection error. The calibrated model has been shown to predict surface overshoot and undershoot trends quite well. Simulations have shown that touch-off error is dominated by part surface roughness.

scholarly journals Parametric Investigation of EP To Enhance Surface Characteristics of Maraging Steel With Organic Electrolyte

2021 ◽  
Author(s):  
Abhinav Kumar ◽  
Suraj Kumar ◽  
Manas Das
Keyword(s):  
Surface Roughness ◽  
Maraging Steel ◽  
Linear Sweep Voltammetry ◽  
Surface Characteristics ◽  
Polished Surface ◽  
Surface Reflectance ◽  
Spectroscopy Analysis ◽  
Initial Value ◽  
Workpiece Surface ◽  
Metal Oxide Layer

Abstract Maraging steel 300 is widely used in aircraft, tools, and automotive industries, which requires a polished surface for better performance. In conventional methods of polishing, the abrasives directly contact the workpiece surface and deteriorate its property. Thus, a non-conventional method like Electropolishing (EP), is utilized to finish maraging steel with acetic acid (99.7 wt.%) and perchloric acid (70 wt.%) mixed in the volume of 3:1. Linear sweep voltammetry (LSV) is performed to determine the passive region that gives the best electropolishing performance. Different parameters, namely temperature, agitation, and polishing time and their effect on surface roughness and surface reflectance, are observed during EP. The optimized process parameters which give the best EP performance are the temperature at 60ºC, rotation of magnetic stirrer at 400 rpm, and polishing time of 6 minutes. An improvement of 56% in surface roughness and 60% in surface reflectance from its initial value of 21% is observed. EP makes the surface hydrophilic as the contact angle changes from 111.2º to 68.6º. Energy-Dispersive X-Ray Spectroscopy analysis suggests that after EP, a metal oxide layer forms on the surface which helps in increasing corrosion resistance.

Effects of Tool Geometry and Workpiece Hardness on Surface Roughness in Finish Hard Turning of AISI 440C

2010 ◽  
Vol 97-101 ◽  
pp. 1815-1818
Author(s):  
Zhen Yu Shi ◽  
Zhan Qiang Liu
Keyword(s):  
Surface Roughness ◽  
Flow Stress ◽  
Hard Turning ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Surface Hardness ◽  
Lower Surface ◽  
Tool Geometry ◽  
Workpiece Surface ◽  
Finish Hard Turning

In this study, the effects of cutting tool geometry and workpiece hardness on surface roughness in finish hard turning of AISI 440C steel were experimental investigated. Four-factor (hardness, tool geometry, feed rate and cutting speed) two-level fractional experiments were conducted and analysis of variance (ANOVA) was performed. This study showed that the effects of workpiece hardness and tool geometry on surface roughness are statistically significant. Especially lower workpiece surface hardness and larger tool nose angle resulted in lower surface roughness because that the surface hardness influences the workpiece’s flow stress and the tool nose angle changes the contact area between the cutting tool and workpiece.

scholarly journals Biofilm inhibition and bactericidal activity of NiTi alloy coated with graphene oxide/silver nanoparticles via electrophoretic deposition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sirapat Pipattanachat ◽  
Jiaqian Qin ◽  
Dinesh Rokaya ◽  
Panida Thanyasrisung ◽  
Viritpon Srimaneepong
Keyword(s):  
Surface Roughness ◽  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Electrophoretic Deposition ◽  
Biofilm Formation ◽  
Niti Alloy ◽  
Surface Characteristics ◽  
Dependent Manner ◽  
Biofilm Inhibition ◽  
Coating Time

AbstractBiofilm formation on medical devices can induce complications. Graphene oxide/silver nanoparticles (GO/AgNPs) coated nickel-titanium (NiTi) alloy has been successfully produced. Therefore, the aim of this study was to determine the anti-bacterial and anti-biofilm effects of a GO/AgNPs coated NiTi alloy prepared by Electrophoretic deposition (EPD). GO/AgNPs were coated on NiTi alloy using various coating times. The surface characteristics of the coated NiTi alloy substrates were investigated and its anti-biofilm and anti-bacterial effect on Streptococcus mutans biofilm were determined by measuring the biofilm mass and the number of viable cells using a crystal violet assay and colony counting assay, respectively. The results showed that although the surface roughness increased in a coating time-dependent manner, there was no positive correlation between the surface roughness and the total biofilm mass. However, increased GO/AgNPs deposition produced by the increased coating time significantly reduced the number of viable bacteria in the biofilm (p < 0.05). Therefore, the GO/AgNPs on NiTi alloy have an antibacterial effect on the S. mutans biofilm. However, the increased surface roughness does not influence total biofilm mass formation (p = 0.993). Modifying the NiTi alloy surface using GO/AgNPs can be a promising coating to reduce the consequences of biofilm formation.

Modeling of surface roughness in a novel magnetorheological gear profile finishing process

2020 ◽  
pp. 095440622097826
Author(s):  
Ravi Datt Yadav ◽  
Anant Kumar Singh ◽  
Kunal Arora
Keyword(s):  
Surface Roughness ◽  
Gear Tooth ◽  
Surface Characteristics ◽  
Spur Gear ◽  
Tooth Profile ◽  
Tooth Surface ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Finishing Process ◽  
Gear Profile

Fine finishing of spur gears reduces the vibrations and noise and upsurges the service life of two mating gears. A new magnetorheological gear profile finishing (MRGPF) process is utilized for the fine finishing of spur gear teeth profile surfaces. In the present study, the development of a theoretical mathematical model for the prediction of change in surface roughness during the MRGPF process is done. The present MRGPF is a controllable process with the magnitude of the magnetic field, therefore, the effect of magnetic flux density (MFD) on the gear tooth profile has been analyzed using an analytical approach. Theoretically calculated MFD is validated experimentally and with the finite element analysis. To understand the finishing process mechanism, the different forces acting on the gear surface has been investigated. For the validation of the present roughness model, three sets of finishing cycle experimentations have been performed on the spur gear profile by the MRGPF process. The surface roughness of the spur gear tooth surface after experimentation was measured using Mitutoyo SJ-400 surftest and is equated with the values of theoretically calculated surface roughness. The results show the close agreement which ranges from −7.69% to 2.85% for the same number of finishing cycles. To study the surface characteristics of the finished spur gear tooth profile surface, scanning electron microscopy is used. The present developed theoretical model for surface roughness during the MRGPF process predicts the finishing performance with cycle time, improvement in the surface quality, and functional application of the gears.

scholarly journals Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1376
Author(s):  
Alex Quok An Teo ◽  
Lina Yan ◽  
Akshay Chaudhari ◽  
Gavin Kane O’Neill
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Characterization ◽  
High Surface ◽  
Surface Characteristics ◽  
Post Processing ◽  
Stainless Steel 316L ◽  
Processing Methods ◽  
Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

Abrasive Waterjet Cutting of Aluminum Alloys: Workpiece Surface Roughness

2013 ◽  
Vol 404 ◽  
pp. 3-9 ◽  
Author(s):  
Nihat Tosun ◽  
Ihsan Dagtekin ◽  
Latif Ozler ◽  
Ahmet Deniz
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Aluminum Alloys ◽  
Abrasive Waterjet ◽  
Traditional Methods ◽  
Workpiece Surface ◽  
Abrasive Waterjet Machining ◽  
Waterjet Machining ◽  
Area Of Application ◽  
Better Than

Abrasive waterjet machining is one of the non-traditional methods of the recent years which found itself a wide area of application in the industry for machining of different materials. In this paper, the surface roughness of 6061-T6 and 7075-T6 aluminum alloys are being cut with abrasive waterjet is examined experimentally. The experiments were conducted with different waterjet pressures and traverse speeds. It has been found that the surface roughness obtained by cutting material with high mechanical properties is better than that of obtained by cutting material with inferior mechanical properties.

Surface Roughness and Cutting Force Components Evaluation in Hard Turning by Differently Shaped Cutting Tools

2016 ◽  
Vol 862 ◽  
pp. 26-32 ◽  
Author(s):  
Michaela Samardžiová
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Hard Turning ◽  
Cutting Tool ◽  
Single Point ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Cutting Force Components ◽  
Force Components

There is a difference in machining by the cutting tool with defined geometry and undefined geometry. That is one of the reasons of implementation of hard turning into the machining process. In current manufacturing processes is hard turning many times used as a fine finish operation. It has many advantages – machining by single point cutting tool, high productivity, flexibility, ability to produce parts with complex shapes at one clamping. Very important is to solve machined surface quality. There is a possibility to use wiper geometry in hard turning process to achieve 3 – 4 times lower surface roughness values. Cutting parameters influence cutting process as well as cutting tool geometry. It is necessary to take into consideration cutting force components as well. Issue of the use of wiper geometry has been still insufficiently researched.

New Development in High Efficiency Deep Grinding

2012 ◽  
Author(s):  
Andre D. L. Batako ◽  
Valery V. Kuzin ◽  
Brian Rowe
Keyword(s):  
Machine Tool ◽  
High Efficiency ◽  
Machining Process ◽  
Depth Of Cut ◽  
Removal Rates ◽  
Workpiece Surface ◽  
New Development ◽  
Cutting Processes ◽  
Selection Of ◽  
Made In

High Efficiency Deep Grinding (HEDG) has been known to secure high removal rates in grinding processes at high wheel speed, relatively large depth of cut and moderately high work speed. High removal rates in HEDG are associated with very efficient grinding and secure very low specific energy comparable to conventional cutting processes. Though there exist HEDG-enabled machine tools, the wide spread of HEDG has been very limited due to the requirement for the machine tool and process design to ensure workpiece surface integrity. HEDG is an aggressive machining process that requires an adequate selection of grinding parameters in order to be successful within a given machine tool and workpiece configuration. This paper presents progress made in the development of a specialised HEDG machine. Results of HEDG processes obtained from the designed machine tool are presented to illustrate achievable high specific removal rates. Specific grinding energies are shown alongside with measured contact arc temperatures. An enhanced single-pole thermocouple technique was used to measure the actual contact temperatures in deep cutting. The performance of conventional wheels is depicted together with the performance of a CBN wheel obtained from actual industrial tests.

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