scholarly journals Scalogram-Based Instantaneous Features of Acoustic Emission in Grinding Burn Detection

2021 ◽  
Author(s):  
Isa Yesilyurt ◽  
◽  
Abdullah Dalkiran ◽  
Onder Yesil ◽  
Ozan Mustak ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Cutting Speed ◽  
Operating Conditions ◽  
Depth Of Cut ◽  
Signal Phase ◽  
Time Frequency ◽  
Grinding Burn ◽  
Frequency Moments ◽  
Phase Deviation ◽  
Instantaneous Energy

Time-frequency methods are effective tools in identifying the frequency content of a signal and revealing its time-variant features. This paper presents the use of instantaneous features (i.e. instantaneous energy and signal phase) of acoustic emission (AE) in the detection of thermal damage to the workpiece in grinding. Both the instantaneous energy and mean frequency are obtained using the low-order frequency moments of a scalogram. While the zero-order frequency moment yields the instantaneous energy, the first-order frequency moment gives the instantaneous frequency by which the signal phase is recovered. The grinding process is monitored using acoustic emission for various operating conditions, including the regular grinding, grinding at a higher cutting speed and larger infeed, and small dressing depth of cut. It has been found that both the instantaneous energy and phase deviation indicate the presence of burn damage and serve as robust and reliable indicators, providing a basis for detecting the grinding burn.

scholarly journals Scalogram-Based Instantaneous Features of Acoustic Emission in Grinding Burn Detection

2021 ◽  
Author(s):  
Isa Yesilyurt ◽  
◽  
Abdullah Dalkiran ◽  
Onder Yesil ◽  
Ozan Mustak ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Cutting Speed ◽  
Operating Conditions ◽  
Depth Of Cut ◽  
Signal Phase ◽  
Time Frequency ◽  
Grinding Burn ◽  
Frequency Moments ◽  
Phase Deviation ◽  
Instantaneous Energy

Time-frequency methods are effective tools in identifying the frequency content of a signal and revealing its time-variant features. This paper presents the use of instantaneous features (i.e. instantaneous energy and signal phase) of acoustic emission (AE) in the detection of thermal damage to the workpiece in grinding. Both the instantaneous energy and mean frequency are obtained using the low-order frequency moments of a scalogram. While the zero-order frequency moment yields the instantaneous energy, the first-order frequency moment gives the instantaneous frequency by which the signal phase is recovered. The grinding process is monitored using acoustic emission for various operating conditions, including the regular grinding, grinding at a higher cutting speed and larger infeed, and small dressing depth of cut. It has been found that both the instantaneous energy and phase deviation indicate the presence of burn damage and serve as robust and reliable indicators, providing a basis for detecting the grinding burn.

Life Prediction of Cutting Tool by the Workpiece Cutting Condition

2011 ◽  
Vol 223 ◽  
pp. 554-563 ◽  
Author(s):  
Noemia Gomes de Mattos de Mesquita ◽  
José Eduardo Ferreira de Oliveira ◽  
Arimatea Quaresma Ferraz
Keyword(s):  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Operating Conditions ◽  
Production Costs ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Workpiece Material ◽  
The Cost

Stops to exchange cutting tool, to set up again the tool in a turning operation with CNC or to measure the workpiece dimensions have direct influence on production. The premature removal of the cutting tool results in high cost of machining, since the parcel relating to the cost of the cutting tool increases. On the other hand the late exchange of cutting tool also increases the cost of production because getting parts out of the preset tolerances may require rework for its use, when it does not cause bigger problems such as breaking of cutting tools or the loss of the part. Therefore, the right time to exchange the tool should be well defined when wanted to minimize production costs. When the flank wear is the limiting tool life, the time predetermination that a cutting tool must be used for the machining occurs within the limits of tolerance can be done without difficulty. This paper aims to show how the life of the cutting tool can be calculated taking into account the cutting parameters (cutting speed, feed and depth of cut), workpiece material, power of the machine, the dimensional tolerance of the part, the finishing surface, the geometry of the cutting tool and operating conditions of the machine tool, once known the parameters of Taylor algebraic structure. These parameters were raised for the ABNT 1038 steel machined with cutting tools of hard metal.

Energy Efficiency in Thermally Assisted Machining of Titanium Alloy: A Numerical Study

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
J. Ma ◽  
X. Ge ◽  
S. Lei
Keyword(s):  
Energy Efficiency ◽  
Titanium Alloy ◽  
Total Energy ◽  
Numerical Study ◽  
Cutting Speed ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Depth Of Cut ◽  
Workpiece Material ◽  
Cutting Energy

This study investigates the energy utilization and efficiency in thermally assisted machining (TAM) of a titanium alloy using numerical simulation. AdvantEdge finite element method (FEM) is used to conduct the simulation of orthogonal machining of the workpiece. Thermal boundary conditions are specified to approximate laser preheating of the workpiece material. The effects of operating conditions (preheat temperature, cutting speed, depth of cut, and rake angle) on mechanical cutting energy, preheat energy, and energy efficiency are investigated. The results show that preheating the workpiece reduces the cutting energy but increases the total energy in TAM. There is significant potential to maximize total energy efficiency in TAM by optimal design of heating strategies and machining conditions.

scholarly journals Application of the Acoustic Emission Method for Diagnosis of On-Load Tap Changer

2017 ◽  
Vol 42 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Henryk Majchrzak ◽  
Andrzej Cichoń ◽  
Sebastian Borucki
Keyword(s):  
Acoustic Emission ◽  
Frequency Domain ◽  
Time Domain ◽  
Operating Conditions ◽  
Time Frequency ◽  
Measurement Results ◽  
Tap Changer ◽  
The Time Domain ◽  
Load Tap Changer ◽  
Short Time

Abstract This paper provides an example of the application of the acoustic emission (AE) method for the diagnosis of technical conditions of a three-phase on-load tap-changer (OLTC) GIII type. The measurements were performed for an amount of 10 items of OLTCs, installed in power transformers with a capacity of 250 MVA. The study was conducted in two different OLTC operating conditions during the tapping process: under load and free running conditions. The analysis of the measurement results was made in both time domain and time-frequency domain. The description of the AE signals generated by the OLTC in the time domain was performed using the analysis of waveforms and determined characteristic times. Within the time-frequency domain the measured signals were described by short-time Fourier transform spectrograms.

Micro-Milling of Hardened AISI D2 Tool Steel

2012 ◽  
Vol 445 ◽  
pp. 62-67 ◽  
Author(s):  
J.B. Saedon ◽  
S.L. Soo ◽  
D.K. Aspinwall ◽  
A. Barnacle
Keyword(s):  
Tool Wear ◽  
Tool Steel ◽  
Feed Rate ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Operating Conditions ◽  
Micro Milling ◽  
Burr Formation ◽  
Depth Of Cut ◽  
Aisi D2

The paper presents an experimental investigation into the slotting of hardened AISI D2 (~62HRC) tool steel using 0.5mm diameter coated (TiAlN) tungsten carbide (WC) end mills. SEM analysis of tool morphology and coating integrity was undertaken on all tools prior to testing. Tool wear details are given based on resulting cutter diameter and slot width reduction. In addition, cutting forces are also presented together with details of workpiece burr formation. A full factorial experimental design was used with variation of cutting speed, feed rate and depth of cut, with results evaluated using analysis of variance (ANOVA) techniques. Parameter levels were chosen based on microscale milling best practice and results from preliminary testing. Main effects plots and percentage contribution ratios (PCR) are included for the main factors. Cutting speed was shown to have the greatest effect on tool wear (33% PCR). When operating at 50m/min cutting speed with a feed rate of 8µm/rev and a depth of cut of 55µm, cutter diameter showed a reduction of up to 82µm for a 520mm cut length. SEM micrographs of tool wear highlighted chipping / fracture as the primary wear mode with adhered workpiece material causing further attritious wear when machining was continued up to 2.6m cut length. All tests produced burrs on the top edges of the slots which varied in size / width to a lesser or greater degree. Under the most severe operating conditions, burr width varied from approximately 50µm to more than 220µm over the 520mm cut length. Cutting forces in general were less than 12N up to test cessation.

Correlation Between Acoustic Emission and Wear of Multi-Layer Ceramic Coated Carbide Tools

1997 ◽  
Vol 119 (2) ◽  
pp. 238-246 ◽  
Author(s):  
S.-S. Cho ◽  
K. Komvopoulos
Keyword(s):  
Acoustic Emission ◽  
Cutting Speed ◽  
Shear Zones ◽  
Machining Process ◽  
Contact Friction ◽  
Depth Of Cut ◽  
Near Surface ◽  
Pull Out ◽  
Ae Signal ◽  
Coated Carbide

Acoustic emission (AE) was used to monitor the machining process and tool condition during turning of AISI 4340 steel with uncoated, two-layer (TiC/Al2O3) coated, and three-layer (TiC/Al2O3/TiN) coated cemented WC-Co tools. The experiments were performed at four different feedrates and constant cutting speed and depth of cut. The variation of the AE signal with cutting time is interpreted in light of the dominant mechanisms, rates, and patterns of wear and the contact friction conditions at the tool/workpiece and tool/chip interfaces. Correlations between intrinsic frequencies and AE sources are identified by examining the root-mean-square, dominant amplitude, type, and count rate of the AE signals. It is shown that AE frequencies in the range of 50–100 kHz are primarily due to plastic deformation in the near-surface tool regions and the primary, secondary, and tertiary shear zones of the workpiece, whereas cracking leading to coating delamination and WC grain pull-out generates frequencies in the range of 170–200 kHz. The tool life estimated from the root-meansquare of the AE signal is shown to be in good agreement with that determined from measurements of the maximum wearland width on the tool nose. The obtained results demonstrate that AE is an effective technique for in-process wear monitoring and wear mechanism identification of multi-layer ceramic coated tools.

Use of Response Surface Methodology to Select a Cutting Tool to Maximize Profit

1976 ◽  
Vol 98 (1) ◽  
pp. 63-65 ◽  
Author(s):  
W. W. Claycombe ◽  
W. G. Sullivan
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Operating Conditions ◽  
Depth Of Cut ◽  
Maximum Profit ◽  
Decision Variables ◽  
Conventional Tests ◽  
Economic Decision Theory

A technique is presented which uses Response Surface Methodology to select a cutting tool in order to maximize profit. Different tools are analyzed to determine what combinations of cutting speed, feed, and depth of cut will give maximum profit for each kind of tool. Only then may different tools be compared. There is a possibility that the tool which is capable of yielding maximum profit may be most economical at operating conditions which are somewhat anomolous. With conventional tests a suboptimal tool may be selected, or the best tool may be used at suboptimal operating conditions. The contribution of this article is the expression of profit as a function of the direct physical decision variables and the subsequent optimization. The use of these techniques with economic decision theory is unique.

Milling Burr Size Estimation Using Acoustic Emission and Cutting Forces

2011 ◽  
Author(s):  
Seyed Ali Niknam ◽  
Azziz Tiabi ◽  
Imed Zaghbani ◽  
Rene Kamguem ◽  
Victor Songmene
Keyword(s):  
Acoustic Emission ◽  
Cutting Forces ◽  
Estimation Method ◽  
Cutting Speed ◽  
Measurement Methods ◽  
Estimation Methods ◽  
Burr Formation ◽  
Depth Of Cut ◽  
Size Estimation ◽  
Burr Size

Burr formation is one of the main concerns usually faced by machining industries. Its presence leads to additional part edge finishing operations that are costly and time consuming. Burrs must be removed as they are source of dimensional errors, jamming and misalignment during assembly. In many cases burrs may injure workers during handling of machined part. Due to burr effect on machined part quality, manufacturing costs and productivity, more focus has been given to burr measurement/estimation methods. Large number of burr measurement methods has been introduced according to various criteria. The selection of appropriate burr size estimation method depends on number of factors such as desired level of quality and requested measuring accuracy. Traditional burr measurement methods are very time consuming and costly. This article aims to present empirical models using acoustic emission (AE) and cutting forces signals to predict entrance and exit burrs size in slot milling operation. These models can help estimating the burrs size without having to measure them. The machining tests were carried on Al 7075-T6 aluminum alloy using 3 levels of cutting speed, 3 levels of feed rate, 3 levels of cutting tool coating and 2 levels of depth of cut. Mathematical models were developed based on most sensitive AE parameters following statistical analysis, cutting forces and their interaction on predicting the entrance and exit burrs size. The proposed models correlate very well with the measured burrs size data.

Energy Efficiency in Thermally Assisted Machining of Titanium Alloy: A Numerical Study

2013 ◽  
Author(s):  
Jianfeng Ma ◽  
Xianchen Ge ◽  
Shuting Lei
Keyword(s):  
Energy Efficiency ◽  
Titanium Alloy ◽  
Total Energy ◽  
Numerical Study ◽  
Cutting Speed ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Depth Of Cut ◽  
Workpiece Material ◽  
Cutting Energy

This study investigates the energy utilization and efficiency in thermally assisted machining (TEM) of a titanium alloy using numerical simulation. AdvantEdge FEM is used to conduct the simulation of orthogonal machining of the workpiece. Thermal boundary conditions are specified to approximate laser preheating of the workpiece material. The effects of operating conditions (preheat temperature, cutting speed, depth of cut, and rake angle) on mechanical cutting energy, preheat energy, and energy efficiency are investigated. The results show that preheating the workpiece reduces the cutting energy but increases the total energy in TEM. There is significant potential to maximize total energy efficiency in TEM by optimal design of heating strategies and machining conditions.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

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