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.

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.

Application of Taguchi and Response Surface Methodologies for Surface Roughness in Rotary Tool Polishing Hardness Mould Steels

2011 ◽  
Vol 87 ◽  
pp. 82-89
Author(s):  
Potejanasak Potejana ◽  
Chakthong Thongchattu
Keyword(s):  
Surface Roughness ◽  
Response Surface ◽  
Laser Scanning ◽  
Cutting Speed ◽  
Optimal Level ◽  
Confocal Laser ◽  
Milling Machine ◽  
Cnc Milling ◽  
Polishing Process ◽  
Cnc Milling Machine

This research proposes a new application of 3-axis CNC milling machine for polishing the 60 HRC hardness steels. The rotary polishing tools are designed by refer to the end-mill ball nose’s design. The diamond powder are coated in rotary polishing tools by resinoid bonding method and concentrated in 4.4 karat/cm2. The Zig-milling tool paths are used to polish the hardness steel. After polishing, the confocal laser scanning microscope is used to analyze the arithmetic mean surface roughness of the hardness steels. The L12 orthogonal array of the Taguchi’s method is selected to conduct the matrix experiment to determine the optimal polishing process parameters. The diamond grit size and cutting speed of the rotary polishing tools, feed rate and step over of the tool path, the depth of polishing process penetration, and polishing time are used to study. The combination of the optimal level for each factor of the hardness steel polishing process are used to study again in the confirmation experiment. The predicted signal to noise ratio of smaller - the better under optimal condition are calculated by using the data from the experiment. The combination of the optimal level for each factor are used to study again in the confirmation experiment and the result show that polishing time was a dominant parameter for the surface roughness and the next was depth of penetration. The response surface design is then used to build the relationship between the input parameters and output responses. The experimental results show that the integrated approach does indeed find the optimal parameters that result in very good output responses in the rotary polishing tools polished hardness mould steel using CNC milling machine. The mean surface roughness of hardness steel polishing process is improved by the diamond rotary tools with the 3-axis CNC milling machine.

The Cutting Speed Influences on Tool Wear of ZTA Ceramic Cutting Tools and Surface Roughness of Work Material Stainless Steel 316L during High Speed Machining

2016 ◽  
Vol 840 ◽  
pp. 315-320 ◽  
Author(s):  
Afifah Mohd Ali ◽  
Norazharuddin Shah Abdullah ◽  
Manimaran Ratnam ◽  
Zainal Arifin Ahmad
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Tool Wear ◽  
High Speed ◽  
Dense Body ◽  
Cutting Speed ◽  
Optical Microscope ◽  
Stainless Steel 316L ◽  
Crater Wear ◽  
Matlab Programming

The purpose of this research is to find the effects of cutting speed on the performance of the ZTA ceramic cutting tool. Three types of ZTA tools used in this study which are ZTA-MgO(micro), ZTA-MgO(nano) and ZTA-MgO-CeO2. Each of them were fabricated by wet mixing the materials, then dried at 100°C before crushed into powder. The powder was pressed into rhombic shape and sintered at 1600°C at 4 hours soaking time to yield dense body. To study the effect of the cutting speed on fabricated tool, machining was performed on the stainless steel 316L at 1500 to 2000 rpm cutting speed. Surface roughness of workpiece was measured and the tool wears were analysed by using optical microscope and Matlab programming where two types of wear measured i.e. nose wear and crater wear. Result shows that by increasing the cutting speed, the nose wear and crater wear increased due to high abrasion. However, surface roughness decreased due to temperature rise causing easier chip formation leaving a good quality surface although the tool wear is increased.

Surface characteristics and machining performance of TiAlN-, TiN- and AlCrN-coated tungsten carbide drills

2018 ◽  
Vol 233 (4) ◽  
pp. 1075-1086 ◽  
Author(s):  
Chaiya Dumkum ◽  
Pakin Jaritngam ◽  
Viboon Tangwarodomnukun
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Tungsten Carbide ◽  
Thrust Force ◽  
Surface Characteristics ◽  
Average Error ◽  
Force Model ◽  
Machining Performance ◽  
Coating Materials ◽  
Drilling Performance

This article presents a comprehensive analysis of surface characteristics and drilling performance of uncoated and coated tungsten carbide drills. The single- and double-layer coatings of TiN, TiAlN and AlCrN were examined in terms of surface roughness, microhardness and crack resistance. In addition, drilling torque and thrust force were experimentally measured and compared to the developed models based on the drilling mechanics and drill geometries. Tool wear and hole surface roughness were also considered to assess the machining performance of different coated tools. The results revealed that all coated drills can offer better cut surface quality, 28% lower cutting loads and longer tool life than the uncoated drills. Although AlCrN was found to be the hardest coating material among the others, it caused large wear on the cutting edges and poor surface roughness of produced holes. The lowest torque and thrust force were achievable using TiN-coated drill, while the use of TiAlN coating resulted in the lowest surface roughness and smallest tool wear. Furthermore, the drilling torque and thrust force model developed in this study were found to correspond to the experimental measures with the average error of 8.4%. The findings of this work could facilitate the selection of coating materials to advance the machining performance.

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

2019 ◽  
Vol 44 (3) ◽  
pp. 281-288 ◽  
Author(s):  
KY Kyaw ◽  
M Otsuki ◽  
MS Segarra ◽  
N Hiraishi ◽  
J Tagami
Keyword(s):  
Surface Roughness ◽  
Calcium Phosphate ◽  
Repeated Measures ◽  
Laser Scanning ◽  
Artificial Saliva ◽  
Color Difference ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Before And After

SUMMARY Objective: To investigate the effect of calcium-phosphate–based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel. Methods and Materials: Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution. Results: One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p<0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains. Conclusions: Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

Precision Cutting of Structured Ceramic Molds with Micro PCD Milling Tool

2011 ◽  
Vol 5 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Hirofumi Suzuki ◽  
◽  
Tatsuya Furuki ◽  
Mutsumi Okada ◽  
Katsuji Fujii ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Tungsten Carbide ◽  
Polycrystalline Diamond ◽  
Micro Milling ◽  
Grinding Wheels ◽  
Form Accuracy ◽  
Structured Surfaces ◽  
Milling Tool ◽  
Milling Tools

Micro milling tools made of PolyCrystalline Diamond (PCD) have been developed to machine ceramic micro dies and molds. Cutting edges are ground with diamond wheels. PCD milling tool wear is evaluated by cutting binder-less tungsten carbide spherical molds and machining structured surfaces for trial. Results of experiments clarified that PCD milling tool life is over 10 times that of resinoid diamond grinding wheels, and that form accuracy was 0.1 µm-0.3 µm P-V and surface roughness was 10 nm Rz.

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