A Comparative Study of Carbide Tools in Drilling of CFRP and CFRP-Ti Stacks

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Kyung-Hee Park ◽  
Aaron Beal ◽  
Dave (Dae-Wook) Kim ◽  
Patrick Kwon ◽  
Jeff Lantrip
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Comparative Study ◽  
Laser Scanning ◽  
Optical Microscope ◽  
Confocal Laser Scanning Microscope ◽  
Measuring System ◽  
Confocal Laser ◽  
Drill Bit ◽  
Twist Drills

A comparative study was conducted to investigate the resulting tool wear and hole quality when drilling the stacks made of titanium (Ti) and carbon-fiber reinforced plastic (CFRP) versus CFRP only plate using micrograin tungsten carbide (WC) twist drills. The experiments were designed to first drill CFRP alone to create 20 holes. Then, CFRP mechanically stacked with Ti was drilled for the next 20 holes with the same drill bit. This process was repeated until drill bit failure. The drilling experiment was performed at two distinct speeds. Scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM) were used for tool wear analysis. Hole size, hole profile, surface roughness, and Ti burrs were analyzed using coordinate measuring system, surface profilometer and optical microscope. The experimental results indicate that the Ti drilling accelerated flank wear while CFRP drilling deteriorated the cutting edge. Entry delamination, hole diameter errors, and surface roughness of the CFRP plate became more pronounced during the drilling of CFRP-Ti stacks when compared with the results from the drilling of CFRP only. Damage to CFRP holes during CFRP-Ti stack drilling may be caused by Ti chips, Ti adhesion on the tool drill margin or the increased instability as the drill bits wear.

A Comparative Study of Carbide Tools in Drilling of CFRP and CFRP-Ti Stacks

2011 ◽  
Author(s):  
Aaron Beal ◽  
Dave Dae-Wook Kim ◽  
Kyung-Hee Park ◽  
Patrick Kwon
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Comparative Study ◽  
Tungsten Carbide ◽  
Laser Scanning ◽  
Optical Microscope ◽  
Measuring System ◽  
Confocal Laser ◽  
Measuring Device ◽  
Twist Drills

A comparative study was conducted to investigate drilling of a titanium (Ti) plate stacked on a carbon fiber reinforced plastic panel. The effects on tool wear and hole quality in drilling using micrograin tungsten carbide (WC) tools were analyzed. The experiments were designed to first drill CFRP alone to create 20 holes. Then CFRP-Ti stacks were drilled for the next 20 holes with the same drill bit. This process was repeated until drill failure. The drilling was done with tungsten carbide (WC) twist drills at two different speeds (high and low). The feed rate was kept the same for each test, but differs for each material drilled. A Scanning Electron Microscope (SEM), and a Confocal Laser Scanning Microscope (CLSM), were used for tool wear analysis. Hole size and profile, surface roughness, and Ti burrs were analyzed using a coordinate measuring system, profilometer, and an optical microscope with a digital measuring device. The experimental results indicate that the Ti drilling accelerated WC flank wear while CFRP drilling deteriorated the cutting edge. Entry delamination, hole diameter errors, and surface roughness of the CFRP plate became more pronounced during drilling of CFRP-Ti stacks, when compared with the results from CFRP only drilling. Damage to CFRP holes during CFRP-Ti stack drilling may be caused by Ti chips, Ti adhesion on the tool outer edge, and increased instability as the drill bits wear.

scholarly journals The Effect of Spray Distance on Porosity, Surface Roughness and Microhardness of WC-10Co-4Cr Coatings Deposited by HVOF

2021 ◽  
Vol 21 (4) ◽  
pp. 99-111
Author(s):  
Monika Górnik ◽  
Ewa Jonda ◽  
Monika Nowakowska ◽  
Leszek Łatka
Keyword(s):  
Surface Roughness ◽  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Contact Method ◽  
Scanning Microscope ◽  
Closed Porosity ◽  
Hvof Process ◽  
Volume Porosity ◽  
Imagej Software

Abstract The paper presents the computational studies on the microstructure of WC-Co-Cr coatings deposited by High Velocity Oxy Fuel spraying (HVOF). The study covers the porosity assessment according to ASTM E2109-01 standard, carried out in ImageJ software, in terms of volume porosity, size and shape of the pores. The evaluation was preceded by scanning electron microscope (SEM) observations at magnifications of 2000x and 5000x. Additionally, topography analysis has been performed by confocal laser scanning microscope (CLSM), and the surface roughness Ra was evaluated by the contact method with use of a stylus profilometer. Finally, the influence of porosity was observed for coatings microhardness HV0.3. According to the results, the total closed porosity was found to be in the range of 5.01 vol.% and 5.38 vol.%. The dominated pores in the coatings were of size 0.1-1.0 μm. Studies showed that HVOF process enabled deposition of dense coatings, characterized by homogenous distribution of pores and low roughness.

scholarly journals Impact of Layer Thickness and Storage Time on the Properties of 3D-Printed Dental Dies

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 509
Author(s):  
Aya Sabbah ◽  
Georgios Romanos ◽  
Rafael Delgado-Ruiz
Keyword(s):  
Surface Roughness ◽  
Layer Thickness ◽  
Dimensional Stability ◽  
Laser Scanning ◽  
Storage Time ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Dimensional Changes ◽  
3D Printed ◽  
And Storage

The purpose of this study was to evaluate the effect of printing layer thickness on the repeatability and surface roughness of 3D-printed dies and detect the effect of layer thickness and storage time on the dimensional stability of 3D-printed dies. One stereolithography (STL) file of an upper molar prepared for a full ceramic crown was used to print three groups of dies: 25 µm, 50 µm, and 100 µm. Repeatability was evaluated by linear and area measurements with a digital caliper and a digital metrology microscope. Dimensional stability was analyzed at 3 weeks, 6 months, and 1 year of storage time. Surface roughness parameters were measured with a 3D confocal laser scanning microscope. Statistics were completed using one-way analysis of variance and Tukey’s post hoc tests, p < 0.05. Printing time decreased as layer thickness increased. All groups showed high repeatability and comparable surface roughness while showing differences in their linear dimensions and surface areas. At the 3 week storage interval, dimensional changes were observed in all groups. Within this experimental study’s constraints, it can be concluded that changing the 3D-printing layer thickness does not affect the repeatability or the surface roughness of the product; meanwhile, changes to the layer thickness and storage time influence the dimensional stability of 3D-printed dies.

Analysis of Transverse Cracks Forming in a Railway Axle

2019 ◽  
Vol 944 ◽  
pp. 404-410 ◽  
Author(s):  
Hong Xiang Yin
Keyword(s):  
Photoelectron Spectroscopy ◽  
Laser Scanning ◽  
Surface Defect ◽  
Optical Microscope ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Spectroscopy Analysis ◽  
Transverse Cracks ◽  
Interference Fit ◽  
Energy Disperse Spectroscopy

Surface defect is the main form of axle failure. In this paper, the cause of surface defect on wheel seat of a certain type of dynamic axle is analyzed systematically. In the test, the macroscopic chemical component of inspection axle was determined using spectrometer. And the chemical composition near the crack was detected by energy disperse spectroscopy and X-ray photoelectron spectroscopy analysis. The microstructure of the crack area was observed by optical microscope, while the crack microscopic characteristic was characterized using scanning electron microscope and confocal laser scanning microscope. The study found that, the defect is transverse crack, which was distributed circumferentially along the wheel seat. Further more, the typical features of wear or friction and iron oxide was observed on the wheel seat near the crack area. It was concluded that, due to surface presure and the existence of stress concentration, which the wheel and axle interference fit resulted in, wear abrasion and fretting fatigue initiated fatigue crack.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

3-Dimensional immunolabeling and in situ hybridization detection using fluorescence photooxidation and intermediate-voltage Electron Microscopy

1994 ◽  
Vol 52 ◽  
pp. 164-165
Author(s):  
Thomas J. Deerinck ◽  
Maryann E. Martone ◽  
Varda Lev-Ram ◽  
David P. L. Green ◽  
Roger Y. Tsien ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Reactive Oxygen ◽  
Confocal Laser Scanning Microscope ◽  
Fluorescent Dye ◽  
Confocal Laser ◽  
3 Dimensional ◽  
Voltage Electron ◽  
Dimensional Distribution ◽  
Electron Microscopes ◽  
New Generation

The confocal laser scanning microscope has become a powerful tool in the study of the 3-dimensional distribution of proteins and specific nucleic acid sequences in cells and tissues. This is also proving to be true for a new generation of high contrast intermediate voltage electron microscopes (IVEM). Until recently, the number of labeling techniques that could be employed to allow examination of the same sample with both confocal and IVEM was rather limited. One method that can be used to take full advantage of these two technologies is fluorescence photooxidation. Specimens are labeled by a fluorescent dye and viewed with confocal microscopy followed by fluorescence photooxidation of diaminobenzidine (DAB). In this technique, a fluorescent dye is used to photooxidize DAB into an osmiophilic reaction product that can be subsequently visualized with the electron microscope. The precise reaction mechanism by which the photooxidation occurs is not known but evidence suggests that the radiationless transfer of energy from the excited-state dye molecule undergoing the phenomenon of intersystem crossing leads to the formation of reactive oxygen species such as singlet oxygen. It is this reactive oxygen that is likely crucial in the photooxidation of DAB.

A confocal laser scanning microscope for fluorescence and reflection at video rates

1989 ◽  
Vol 47 ◽  
pp. 134-135
Author(s):  
P.M. Houpt ◽  
A. Draaijer
Keyword(s):  
Light Source ◽  
Laser Scanning ◽  
Focal Point ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Point Light Source ◽  
Volume Of Interest ◽  
Ion Laser ◽  
Point Light ◽  
Point Detector

In confocal microscopy, the object is scanned by the coinciding focal points (confocal) of a point light source and a point detector both focused on a certain plane in the object. Only light coming from the focal point is detected and, even more important, out-of-focus light is rejected.This makes it possible to slice up optically the ‘volume of interest’ in the object by moving it axially while scanning the focused point light source (X-Y) laterally. The successive confocal sections can be stored in a computer and used to reconstruct the object in a 3D image display.The instrument described is able to scan the object laterally with an Ar ion laser (488 nm) at video rates. The image of one confocal section of an object can be displayed within 40 milliseconds (1000 х 1000 pixels). The time to record the total information within the ‘volume of interest’ normally depends on the number of slices needed to cover it, but rarely exceeds a few seconds.

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