Tool Pre-Failure Monitoring in Intermittent Cutting Operations

2016 ◽  
Author(s):  
M. Hassan ◽  
A. Sadek ◽  
A. Damir ◽  
M. H. Attia ◽  
V. Thomson
Keyword(s):  
Tool Wear ◽  
Failure Modes ◽  
Impact Load ◽  
Research Work ◽  
Unstable Crack ◽  
Tool Failure ◽  
Milling Operations ◽  
High Feed ◽  
Rough Milling ◽  
Intermittent Cutting

Tool failure remains one of the most challenging phenomena in machining that affects the productivity and product quality, and hence the cost. In high feed rough milling operations of hard-to-cut materials, chipping and breakage have been observed as the dominant failure modes of the end mill cutters. Most of the work in the open literature is focusing on either detecting the complete tool breakage after it takes place or detecting the progressive tool wear. Detecting the abrupt/sudden tool failure due to tool chipping before it takes place, which is essential to avoid any damage to the machined part, has not been addressed. Therefore, the main objective of this research work is to investigate the ability of using the process monitoring signals in order to detect the tool pre-failure and failure by chipping/breakage in intermittent cutting operations. A method was devised to induce impact load on the cutting tool tip to study the features of signals collected by various sensors due to unstable crack propagation and chipping, while ensuring minimal tool wear effect. The acoustic emission (AE) signal features were able to successfully capture tool pre-failure, while other signals could detect the failure occurrence only.

Study on Cutting Performance of the Alumina Based Nanocomposite Ceramic Tool

2014 ◽  
Vol 941-944 ◽  
pp. 1917-1921
Author(s):  
Qi Fen Zhou ◽  
Peng Zhou ◽  
Hai Ying Zhang
Keyword(s):  
Tool Wear ◽  
Failure Modes ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Cutting Performance ◽  
Crater Wear ◽  
Tool Failure ◽  
Ceramic Tools ◽  
Ceramic Cutting Tool ◽  
Adhesion Wear

In this paper, the oxide nanometer composite cutting performance of ceramic tools cutting cast iron were studied. And the tool failure modes were mainly analyzed. Through the study found that, with the increase of tool wear with cutting speed, failure forms mainly adhesion wear. When the cutting speed is low, the knife before the crater wear become the main form of ceramic cutting tool wear, boundary wear and the surface of the knife after wear is also very serious. And in the process of cutting, the collapse edge can also occur now; With the increase of cutting speed, collapse become the main failure forms of cutter blade.

Effect of tool wear on chip formation during dry machining of Ti-6Al-4V alloy, part 2: Effect of tool failure modes

2015 ◽  
Vol 231 (9) ◽  
pp. 1575-1586 ◽  
Author(s):  
Shoujin Sun ◽  
Milan Brandt ◽  
Matthew S Dargusch
Keyword(s):  
Plastic Deformation ◽  
Tool Wear ◽  
Failure Modes ◽  
Flank Wear ◽  
Cutting Tools ◽  
Cutting Edge ◽  
Machined Surface ◽  
Tool Failure ◽  
Geometric Ratio ◽  
Cutting Speeds

Variation in the geometric and surface features of segmented chips with an increase in the volume of material removed and tool wear has been investigated at cutting speeds of 150 and 220 m/min at which the cutting tools fail due to gradual flank wear and plastic deformation of the cutting edge, respectively. Among the investigated geometric variables of the segmented chips, slipping angle, undeformed surface length, segment spacing, degree of segmentation and chip width showed the different variation trends with an increase in the volume of material removed or flank wear width, and achieved different values when tool failed at different cutting speeds. However, the chip geometric ratio showed a similar variation trend with an increase in the volume of material removed and flank wear width, and achieved the similar value at the end of tool lives at cutting speeds of both 150 and 220 m/min regardless of the different tool failure modes. Plastic deformation of the tool cutting edge results in severe damage on the machined surface of the chip and significant compression deformation on the undeformed surface of the chip.

Study on damage behavior of carbide tool for milling difficult-to-machine material

2018 ◽  
Vol 233 (2) ◽  
pp. 735-747
Author(s):  
Yao-Nan Cheng ◽  
Wan-Ying Nie ◽  
Rui Guan ◽  
Wei-Kun Jia ◽  
Fu-gang Yan
Keyword(s):  
Failure Modes ◽  
Impact Load ◽  
Impact Damage ◽  
High Plasticity ◽  
Carbide Tool ◽  
Machine Material ◽  
Tool Failure ◽  
Damage Behavior ◽  
Tool Damage ◽  
The Impact

Water chamber head is an important component of nuclear power unit, and the main material is 508 III steel of difficult-to-machine material, which has the characteristics of high hardness, high strength, high plasticity and high profile shrinkage, etc. During the milling process, the tool is subjected to the cyclic impact load, which make cutting force and cutting heat change violent and occurrence of tool damage failure accelerate. In this paper, the damage behavior of carbide tool for milling difficult-to-machine material is studied first, and then field experiment was carried out on 508 III steel material, tool failure modes were analyzed, which include impact damage and fatigue fracture, and the failure theory and the crack propagation of carbide material were investigated in the process of tool damage. Then, the impact damage model of carbide tool is established based on the classical strength theory, and the critical condition of impact damage is determined according to simulation analysis. Finally, the theoretical model of carbide tool fatigue life is established and the tool fatigue limit is analyzed. Theoretical basis and technical support are provided for the tool failure mechanisms analysis, life prediction, parameter optimization, tool design and development aspects during the study.

Tool Performance in High Speed Finish Milling of Ti6Al4V

Manufacturing ◽  
2002 ◽  
Author(s):  
D. Barnett-Ritcey ◽  
M. A. Elbestawi
Keyword(s):  
Tool Wear ◽  
High Speed ◽  
Flank Wear ◽  
Tool Failure ◽  
Tool Materials ◽  
Fine Grained ◽  
Life Tool ◽  
Tool Performance ◽  
High Feed ◽  
Coated Carbide

High feed rates may be achieved when finish milling titanium (Ti6AI4V) alloy (300HB) at speeds of 152–305 m/min (500–1000sfm). Three tool materials (micro-grain C2 carbide, fine-grained C2 carbide, and a TiAIN coated carbide) were tested using liquid (flood and through-spindle coolant (TSC) at pressures of 2.07 MPa), pressurized air (69–689 kPa (10–100psi)), and dry (no coolant) coolant conditions to prolong tool life. Tool wear manifested itself in two distinct patterns, gradual flank wear or micro-chipping leading to gross fracture. Which of these will lead to tool failure, will depend largely on the ability of the coolant to cool the tool (retard flank wear) without inducing thermal shock. Typically, under pressurized air, speeds up to 267 m/min (875sfm) and chip loads of 0.057–0.114 mm (0.00225–0.0045") may be attained.

ANN-Based Relaying Algorithm for Protection of SVC- Compensated AC Transmission Line and Criticality Analysis of a Digital Relay

2020 ◽  
Vol 13 (3) ◽  
pp. 381-393
Author(s):  
Farhana Fayaz ◽  
Gobind Lal Pahuja
Keyword(s):  
Transmission Line ◽  
Failure Modes ◽  
Reactive Power ◽  
Circuit Breaker ◽  
Research Work ◽  
Back Propagation ◽  
Static Var Compensator ◽  
Data Set ◽  
Ac Transmission ◽  
Criticality Analysis

Background:The Static VAR Compensator (SVC) has the capability of improving reliability, operation and control of the transmission system thereby improving the dynamic performance of power system. SVC is a widely used shunt FACTS device, which is an important tool for the reactive power compensation in high voltage AC transmission systems. The transmission lines compensated with the SVC may experience faults and hence need a protection system against the damage caused by these faults as well as provide the uninterrupted supply of power.Methods:The research work reported in the paper is a successful attempt to reduce the time to detect faults on a SVC-compensated transmission line to less than quarter of a cycle. The relay algorithm involves two ANNs, one for detection and the other for classification of faults, including the identification of the faulted phase/phases. RMS (Root Mean Square) values of line voltages and ratios of sequence components of line currents are used as inputs to the ANNs. Extensive training and testing of the two ANNs have been carried out using the data generated by simulating an SVC-compensated transmission line in PSCAD at a signal sampling frequency of 1 kHz. Back-propagation method has been used for the training and testing. Also the criticality analysis of the existing relay and the modified relay has been done using three fault tree importance measures i.e., Fussell-Vesely (FV) Importance, Risk Achievement Worth (RAW) and Risk Reduction Worth (RRW).Results:It is found that the relay detects any type of fault occurring anywhere on the line with 100% accuracy within a short time of 4 ms. It also classifies the type of the fault and indicates the faulted phase or phases, as the case may be, with 100% accuracy within 15 ms, that is well before a circuit breaker can clear the fault. As demonstrated, fault detection and classification by the use of ANNs is reliable and accurate when a large data set is available for training. The results from the criticality analysis show that the criticality ranking varies in both the designs (existing relay and the existing modified relay) and the ranking of the improved measurement system in the modified relay changes from 2 to 4.Conclusion:A relaying algorithm is proposed for the protection of transmission line compensated with Static Var Compensator (SVC) and criticality ranking of different failure modes of a digital relay is carried out. The proposed scheme has significant advantages over more traditional relaying algorithms. It is suitable for high resistance faults and is not affected by the inception angle nor by the location of fault.

scholarly journals Influence of Tool Wear on Form Deviations in Dry Machining of UNS A97075 Alloy

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 958
Author(s):  
Francisco Javier Trujillo Vilches ◽  
Sergio Martín Béjar ◽  
Carolina Bermudo Gamboa ◽  
Manuel Herrera Fernández ◽  
Lorenzo Sevilla Hurtado
Keyword(s):  
Tool Wear ◽  
General Trend ◽  
Cutting Speed ◽  
Main Tool ◽  
Cutting Parameters ◽  
Adhesion Wear ◽  
Tool Wear Mechanisms ◽  
Tool Wear Mechanism ◽  
High Feed ◽  
Dry Conditions

Geometrical tolerances play a very important role in the functionality and assembly of parts made of light alloys for aeronautical applications. These parts are frequently machined in dry conditions. Under these conditions, the tool wear becomes one of the most important variables that influence geometrical tolerances. In this work, the influence of tool wear on roundness, straightness and cylindricity of dry-turned UNS A97075 alloy has been analyzed. The tool wear and form deviations evolution as a function of the cutting parameters and the cutting time has been assessed. In addition, the predominant tool wear mechanisms have been checked. The experimental results revealed that the indirect adhesion wear (BUL and BUE) was the main tool-wear mechanism, with the feed being the most influential cutting parameter. The combination of high feed and low cutting speed values resulted in the highest tool wear. The analyzed form deviations showed a general trend to increase with both cutting parameters. The tool wear and the form deviations tend to increase with the cutting time only within the intermediate range of feed tested. As the main novelty, a relationship between the cutting parameters, the cutting time (and, indirectly, the tool wear) and the analyzed form deviations has been found.

Modeling of Cutting Process with Cutter Axis Inclination

2011 ◽  
Vol 223 ◽  
pp. 66-74 ◽  
Author(s):  
Takashi Matsumura
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Cutting Temperature ◽  
Cutting Process ◽  
Mechanistic Models ◽  
End Mill ◽  
High Quality ◽  
Ball End Mill ◽  
Milling Operations ◽  
Edge Roughness

Multi-axis controlled machining has been increasing with the demand for high quality in mold manufacturing. The cutter axis inclination should be properly determined in the milling operations. The paper discusses the cutting process of ball end mill with the cutter axis inclination. Two mechanistic models are presented to show the effect of the cutter axis inclination on the tool wear and the surface finish. The actual cutting time during a rotation of the cutter reduces with increasing the cutter axis inclination. Then, the tool is cooled in the non-cutting time. The tool wear is suppressed with reducing the cutting temperature. The surface finish is also improved by increasing cutting velocities with the cutter axis inclination. When the cutter is inclined in the feed direction, the effect of the edge roughness on the surface finish is eliminated. The discussion based on the simulation is verified in the cutting tests for brittle materials.

scholarly journals Surface Integrity Investigation to Determine Rough Milling Effects for Assessment of Machining Allowance for Subsequent Finish Milling of Alloy 718

2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Jonas Holmberg ◽  
Anders Wretland ◽  
Johan Berglund ◽  
Tomas Beno ◽  
Anton Milesic Karlsson
Keyword(s):  
Surface Integrity ◽  
Milling Process ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Milling Operations ◽  
Milling Operation ◽  
Machining Allowance ◽  
Rough Milling

The planned material volume to be removed from a blank to create the final shape of a part is commonly referred to as allowance. Determination of machining allowance is essential and has a great impact on productivity. The objective of the present work is to use a case study to investigate how a prior rough milling operation affects the finish machined surface and, after that, to use this knowledge to design a methodology for how to assess the machining allowance for subsequent milling operations based on residual stresses. Subsequent milling operations were performed to study the final surface integrity across a milled slot. This was done by rough ceramic milling followed by finish milling in seven subsequent steps. The results show that the up-, centre and down-milling induce different stresses and impact depths. Employing the developed methodology, the depth where the directional influence of the milling process diminishes has been shown to be a suitable minimum limit for the allowance. At this depth, the plastic flow causing severe deformation is not present anymore. It was shown that the centre of the milled slot has the deepest impact depth of 500 µm, up-milling caused an intermediate impact depth of 400 µm followed by down milling with an impact depth of 300 µm. With merged envelope profiles, it was shown that the effects from rough ceramic milling are gone after 3 finish milling passes, with a total depth of cut of 150 µm.

Benchmarking the risk assessment in green supply chain using fuzzy approach to FMEA

2018 ◽  
Vol 25 (8) ◽  
pp. 2660-2687 ◽  
Author(s):  
Sachin Kumar Mangla ◽  
Sunil Luthra ◽  
Suresh Jakhar
Keyword(s):  
Risk Assessment ◽  
Supply Chain ◽  
Failure Mode ◽  
Failure Modes ◽  
Research Work ◽  
Evaluation Framework ◽  
Green Supply Chain ◽  
Content Type ◽  
Efficient Management ◽  
Fmea Analysis

PurposeThe purpose of this paper is to facilitate green supply chain (GSC) managers and planners to model and access GSC risks and probable failures. This paper proposes to use the fuzzy failure mode and effects analysis (FMEA) approach for assessing the risks associated with GSC for benchmarking the performance in terms of effective GSC management adoption and sustainable production.Design/methodology/approachInitially, different failure modes are defined using FMEA analysis, and in order to decide the risk priority, the risk priority number (RPN) is determined. Such priority numbers are typically acquired from the judgment decisions of experts that could contain the element of vagueness and imperfection due to human biases, and it may lead to inaccuracy in the process of risk assessment in GSC. In this study, fuzzy logic is applied to conventional FMEA to overcome the issues in assigning RPNs. A plastic manufacturer GSC case exemplar of the proposed model is illustrated to present the authenticity of this method of risk assessment.FindingsResults indicate that the failure modes, given as improper green operating procedure, i.e. process, operations, etc. (R6), and green issues while closing the loop of GSC (R14) hold the highest RPN and FRPN scores in classical as well as fuzzy FMEA analysis.Originality/valueThe present research work attempts to propose an evaluation framework for risk assessment in GSC. This paper explores both sustainable developments and risks related to efficient management of GSC initiatives in a plastic industry supply chain context. From a managerial perspective, suggestions are also provided with respect to each failure mode.

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