Characteristics of Acoustic Emission Signals in Machining Using Diamond Coated Tools

2008 ◽  
Author(s):  
Jianwen Hu ◽  
Feng Qin ◽  
Kevin Chou ◽  
Raymond G. Thompson
Keyword(s):  
Acoustic Emission ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
High Strength ◽  
Cost Effective ◽  
Fast Fourier Transformation ◽  
Coated Tools ◽  
Coating Delamination ◽  
Pcd Tools ◽  
Ae Signals

Diamond coated cutting tools have been pursued as a cost-effective substitute to brazed polycrystalline diamond (PCD) tools in applications such as machining high-strength and lightweight materials. However, coating delamination has been known as the major failure mode of diamond coated tools, which terminates tool life prematurely. Once delamination failure occurs, the tool substrate often subjects to severe abrasive wear leading to catastrophic tool failures that imparts the part quality and interrupts machining operations. Hence, accurate detections and forecasts of coating delamination events can prevent production loss and assist process planning. In this study, the characteristics of acoustic emission (AE) signals when machining a high-strength aluminum alloy and a composite using diamond coated cutting tools were investigated. The AE signals were analyzed in both time and frequency domains at various machining conditions and different cutting times. It was found that AE root-mean-square values decrease considerably once coating delamination occurs. The results also indicate a correlation between the tool condition and fast Fourier transformation (FFT) spectra of AE raw data. In addition, the machining experiments implied that it may be feasible to use AE signals to monitor the condition of diamond coated tools during machining.

AE Signal Evolutions in Machining by Diamond Coated Tools

2009 ◽  
Author(s):  
Ping Lu ◽  
Y. Kevin Chou ◽  
Raymond G. Thompson
Keyword(s):  
Cutting Tools ◽  
Low Frequency ◽  
Polycrystalline Diamond ◽  
Fast Fourier Transformation ◽  
Part Quality ◽  
Coated Tools ◽  
Coating Failure ◽  
Coating Delamination ◽  
Wear Mode ◽  
Ae Signal

Diamond coated cutting tools have a potential to replace costly polycrystalline diamond tools. However, coating delaminations remain the primary wear mode that often results in catastrophic tool failures, causing to poor part quality and possible damage to machine tools. Moreover, delamination events are difficult to be precisely predicted. Thus, tool delamination identification is necessary for process monitoring. Following a previous work, this study examines the acoustic emission (AE) signal evolutions during machining by diamond coated tools, in particular, the frequency response along cutting time as well as during a specific cutting pass. The intent was to correlate the characteristics of the AE spectral components with coating delaminations. The results are summarized as follows. Though AE root-mean-square values have been used to monitor tool failure, it may not show clear transition registered to coating delamination in some cases. The fast Fourier transformation (FFT) spectra of AE data along cutting time generally show decreased intensity for low frequency peaks, but increased intensity for high frequency peaks. In addition, the AE FFT spectra of sub-divided time zones during one cutting pass may clearly indicate the coating failure transition.

Development of the Hole Generation Technology for Aircraft CFRP Parts

2012 ◽  
Vol 523-524 ◽  
pp. 226-231 ◽  
Author(s):  
Hitoshi Fukagawa ◽  
Toshiki Hirogaki ◽  
Takao Kato ◽  
Atsushi Kato ◽  
Masako Seki
Keyword(s):  
Polycrystalline Diamond ◽  
Reinforced Plastics ◽  
Aerospace Applications ◽  
Coated Tools ◽  
Drilling Method ◽  
Efficiency Cost ◽  
Novel Method ◽  
Drill Holes ◽  
Pcd Tools ◽  
Hole Generation

Carbon fiber-reinforced plastics (CFRP), which are now used in some aerospace applications, is difficult to cut and drill holes in. Moreover, no reports have focused on selecting a suitable drilling method for each aerospace part. This paper discusses many methods of hole generation for CFRP composites, including methods using traditional drill tools and non-traditional methods such as abrasive water jet (AWJ), laser beam and abrasive blast. We look at traditional cemented carbide material tools, polycrystalline diamond (PCD) tools, diamond-like carbon (DLC) coated tools and ceramic tools. Then, comparing the experimental results of these methods from the viewpoints of characteristics, efficiency, cost, and hole quality, we investigate each problem to select the suitable drilling method. As a result, we propose a novel method to strategically obtain the best solutions to generate holes in aerospace parts.

Scribing Characteristics of Glass Plate with Ground PCD Scribing Wheel

2018 ◽  
Vol 12 (5) ◽  
pp. 760-766
Author(s):  
Yusuke Akiyama ◽  
Mutsumi Okada ◽  
Hirofumi Suzuki ◽  
Toshio Fukunishi ◽  
Yoshiyuki Asai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Glass Plate ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Diamond Wheel ◽  
Precision Machining ◽  
Electric Discharge Machining ◽  
Single Crystal Diamond ◽  
Pcd Tools ◽  
Alloy Metal

Polycrystalline diamond (PCD) tools are widely used for cutting tools because PCD has no crystal orientation and is an isotropic material, it is low in cost, and it is easily machined by electric discharge machining. PCD is sintered from diamond abrasives with an alloy metal, such as cobalt, and it is difficult to reduce the surface roughness and the edge accuracy compared with single crystal diamond. In this study, high efficiency and high precision machining of the PCD wheel were investigated. In the experiments, PCD wheels were ground with a diamond wheel, and the effects of the grinding direction and the load on the tool preciseness and the scribing performance were examined.

Tool Wear Characters in Micro-Milling of Fully Sintered ZrO2 Ceramics by Diamond Coated End Mills

2012 ◽  
Vol 723 ◽  
pp. 365-370 ◽  
Author(s):  
Rong Bian ◽  
Eleonora Ferraris ◽  
Jun Qian ◽  
Dominiek Reynaerts ◽  
Liang Li ◽  
...  
Keyword(s):  
Tool Wear ◽  
Cutting Tools ◽  
Chemical Vapour ◽  
Cutting Parameters ◽  
Micro Milling ◽  
Machined Surface ◽  
Coated Tools ◽  
Machined Surface Quality ◽  
Coating Delamination ◽  
End Mills

This work presents an experimental investigation on micro-milling of fully sintered Zirconia (ZrO2) by diamond coated tools. The experiments were conducted on a Kern MMP 2522 micro-milling centre and WC micro end mills, diamond coated by chemical vapour deposition (CVD) and of stiff geometry were employed as cutting tools. The effects of cutting parameters and milling time on tool wear were investigated. The results revealed that the tool wear characters included diamond coating delamination and wear of substrate WC. Both cutting forces and machined surface quality were affected by tool wear with the progress of milling.

Thinning Silicon Wafer with Polycrystalline Diamond Tools

2009 ◽  
Vol 404 ◽  
pp. 157-163
Author(s):  
Pei Lum Tso ◽  
Cheng Huan Chen
Keyword(s):  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Wafer Surface ◽  
Depth Of Cut ◽  
Entire Surface ◽  
Machined Surface ◽  
Drill Bits ◽  
Ductile Mode ◽  
Critical Depth Of Cut ◽  
Pcd Tools

Sintered polycrystalline diamond (PCD) compacts are normally used for cutting tools, drill bits and wire dies. A novel application of PCD has been developed to use its entire surface carved to create different patterns which are triangle or square shape loaded with leveled millers that can shave brittle materials in ductile mode. Due to numerous cutting edges formed on the same level of PCD tools, which can be used to thin the wafer surface to achieve both flatness and smoothness of the industrial requirements. SEM has been used to observe the surface and subsurface of the thinned wafer surface. The critical depth of cut between ductile and brittle cutting mode is close to 2 µm in this thinning operation. The damaged layers of machined surface have been observed and studied in this paper.

Acoustic Emission Signals in the Micro-EDM of PCD

2008 ◽  
Vol 33-37 ◽  
pp. 1181-1186 ◽  
Author(s):  
M. Mahardika ◽  
Kimiyuki Mitsui ◽  
Zahari Taha
Keyword(s):  
Acoustic Emission ◽  
Elastic Wave ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Polycrystalline Diamond ◽  
Micro Edm ◽  
Micro Electrical Discharge Machining ◽  
Single Discharge ◽  
Ae Signals

The mechanism of fracture in micro-electrical discharge machining (-EDM) processes is related to the discharge pulses energy. This paper investigates the correlation of fractures and discharge pulses energy in the -EDM of polycrystalline diamond (PCD) to the acoustic emission (AE) signals. The evaluation of fracture mechanism was done by measuring the generation and propagation of elastic wave in single discharge pulse by using AE sensor. The results show a strong correlation between fractures and discharge pulses energy to the AE signals and mechanism of material removal in the -EDM processes.

scholarly journals Study of cutting force and tool wear during turning of aluminium with WC, PCD and HFCVD coated MCD tools

2020 ◽  
Vol 7 ◽  
pp. 27
Author(s):  
Sisira Kanta Pattnaik ◽  
Minaketan Behera ◽  
Sachidananda Padhi ◽  
Pusparaj Dash ◽  
Saroj Kumar Sarangi
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Cutting Force ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Machining Process ◽  
Pcd Tool ◽  
Rolled Aluminum ◽  
Pcd Tools

Enormous developmental work has been made in synthesis of metastable diamond by hot filament chemical vapor deposition (HFCVD) method. In this paper, micro-crystalline diamond (MCD) was deposited on WC–6 wt.% Co cutting tool inserts by HFCVD technique. The MCD coated tool was characterized by the scanning electron microscope (SEM), X-ray diffraction (XRD) and micro Raman spectroscopy (μ-RS). A comparison was made among the MCD tool, uncoated tungsten carbide (WC) tool and polycrystalline diamond (PCD) tool during the dry turning of rolled aluminum. The various major tests were conducted such as surface roughness, cutting force and tool wear, which were taken into consideration to establish a proper comparison among the advanced cutting tools. Surface roughness was measured during machining by Talysurf. The tool wear was studied by SEM after machining. The cutting forces were measured by Kistler 3D-dynamometer during the machining process. The test results indicate that, the CVD coated MCD tool and PCD tool produced almost similar results. But, the price of PCD tools are five times costlier than MCD tools. So, MCD tool would be a better alternative for machining of aluminium.

scholarly journals PERFORMANCE OF COATED CUTTING TOOLS IN MACHINING: A REVIEW

2020 ◽  
Author(s):  
Rukmini Srikant Revuru ◽  
Vamsi Krishna Pasam ◽  
Nageswara Rao Posinasetti
Keyword(s):  
High Temperatures ◽  
Elevated Temperatures ◽  
Materials Science ◽  
Cutting Tools ◽  
High Strength ◽  
Premature Failure ◽  
Aerospace Applications ◽  
Coated Tools ◽  
Intermediate Layers ◽  
Carbide Inserts

Rapid advances in materials science have prompted the development of materials and alloys of enhanced properties like high strength, hardness, etc. Though these alloys are beneficial in their applications, their machining is difficult. For instance, Inconel 718, a nickel-based alloy, is used in several aerospace applications. This alloy can retain its strength at high temperatures up to 750℃. However, machining Inconel is a problem due to its poor machinability. Similarly, titanium alloys are not very hard but react with tools at high temperatures and lead to their premature failure. Carbide inserts are commonly used as cutting tools in the industry. Carbide tools are manufactured using powder metallurgy technique and possess high strength and hardness, even at elevated temperatures. However, these tools are not effective in machining of “difficult-to-machine” materials and have very short life. In light of this, coated tools have evolved. The cutting tools are coated using very hard, non-reacting material and sometimes a solid lubricant. The coatings are made usually by using PVD or CVD techniques. Often, intermediate layers are provided to improve adhesion between the substrate and the actual coating. Coated tools have better resistance to temperatures and hence, better tool life compared to the regular cutting tools. This paper deals with the evolution of the technology of coated tools. Different types of coatings, their advantages/limitations and efficacy of coated tools in machining are reviewed and discussed.

Acoustic Emission Study of Growth Process of Diamond Crystals under HPHT

2010 ◽  
Vol 146-147 ◽  
pp. 810-813
Author(s):  
Lei Liu ◽  
Qing Cai Su ◽  
Mu Sen Li
Keyword(s):  
Acoustic Emission ◽  
Growth Process ◽  
Synthetic Diamond ◽  
Diamond Growth ◽  
Fast Fourier Transformation ◽  
Frequency Spectra ◽  
Diamond Crystals ◽  
Emission Study ◽  
Acoustic Emission Study ◽  
Ae Signals

The growth process of synthetic diamond single crystals under high-pressure and high-temperature (HPHT) was investigated using acoustic emission (AE) technique. And AE parameters corresponding to growth process were analyzed. However, the AE features of diamond growth are relativelyweak and easily obscured by other AE sources. So the fast Fourier transformation (FFT) was used to calculate the frequency spectra of AE signals for identifying different AE sources. The results showed that the variation of AE counts and energy is in a good agreement with the formation process of synthetic diamond crystals. And the AE signals pronounced from diamond growth are concentrated in the frequency range from 100 to 250 kHz. Thus, AE technique is an effective way to monitor and study the diamond growth, and the frequency analysis can be a useful way to identify different AE sources.

Performance of Cutting Tools in High Speed Milling of SiCp/Al Composites

2012 ◽  
Vol 591-593 ◽  
pp. 311-314 ◽  
Author(s):  
Yang Jun Wang ◽  
Ming Qiang Pan ◽  
Tao Chen ◽  
Ji Zhu Liu ◽  
Li Guo Chen
Keyword(s):  
High Speed ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Optical Microscope ◽  
Coated Tools ◽  
Tools Wear ◽  
Pcd Tools

This paper presents an experimental study in milling of SiCp/Al composites on a high precision machine by using chemical vapor deposition(CVD) diamond coated tools and polycrystalline diamond (PCD) tools. The tool wear was observed and measured by an optical microscope and a scanning electron microscope (SEM). The results show that the coating rupture causes the failure of the CVD diamond coated tools. The PCD tools’ wear is less. At the relatively low cutting speed, the wear pattern of PCD tools is the flank wear which caused by the abrasion of SiC particles. Due to the low cutting temperature, the graphitization of PCD tools does not happen. The wear mechanism of PCD tools will be the abrasive and adhesive wear.

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