scholarly journals Wear analysis in cutting tools by the technique of image processing with the application of two-dimensional matrices

2021 ◽  
Vol 2139 (1) ◽  
pp. 012018
Author(s):  
J H Arévalo-Ruedas ◽  
E Espinel-Blanco ◽  
E Florez-Solano

Abstract The useful life of the tools is a very important economic factor in the metal industry, so any improvement of the tool or material that can extend the useful life of the tools is productive. Tool deterioration can cause damage, cracking and vibration to the tool, and even damage to the machine. Effective tool wear control is most important. Effective tool wear control is most important. At present, there are some tools that can obtain the necessary conditions through digital image processing, and study their lifespan according to their work cycle, as well as the types of possible relationships between the pixels of the image and the different modes of operation, allowing the extraction or isolation of the objects considered. This work analyzes the wear of the tool with the application of two-dimensional matrices with the toolbox of the MATLAB software, which allows to monitor the status of the inserts with the comparison of images in gray scales, in addition, a method of analysis based on interfaces is also being studied; through it, users can access the database that has been implemented, as well as a set of images used to verify the functions developed, determining the wear on the cutting tool.

2021 ◽  
Vol 11 (11) ◽  
pp. 5011
Author(s):  
Yuanxing Huang ◽  
Zhiyuan Lu ◽  
Wei Dai ◽  
Weifang Zhang ◽  
Bin Wang

In manufacturing, cutting tools gradually wear out during the cutting process and decrease in cutting precision. A cutting tool has to be replaced if its degradation exceeds a certain threshold, which is determined by the required cutting precision. To effectively schedule production and maintenance actions, it is vital to model the wear process of cutting tools and predict their remaining useful life (RUL). However, it is difficult to determine the RUL of cutting tools with cutting precision as a failure criterion, as cutting precision is not directly measurable. This paper proposed a RUL prediction method for a cutting tool, developed based on a degradation model, with the roughness of the cutting surface as a failure criterion. The surface roughness was linked to the wearing process of a cutting tool through a random threshold, and accounts for the impact of the dynamic working environment and variable materials of working pieces. The wear process is modeled using a random-effects inverse Gaussian (IG) process. The degradation rate is assumed to be unit-specific, considering the dynamic wear mechanism and a heterogeneous population. To adaptively update the model parameters for online RUL prediction, an expectation–maximization (EM) algorithm has been developed. The proposed method is illustrated using an example study. The experiments were performed on specimens of 7109 aluminum alloy by milling in the normalized state. The results reveal that the proposed method effectively evaluates the RUL of cutting tools according to the specified surface roughness, therefore improving cutting quality and efficiency.


Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.


2022 ◽  
Author(s):  
Yifan Li ◽  
Yongyong Xiang ◽  
Baisong Pan ◽  
Luojie Shi

Abstract Accurate cutting tool remaining useful life (RUL) prediction is of significance to guarantee the cutting quality and minimize the production cost. Recently, physics-based and data-driven methods have been widely used in the tool RUL prediction. The physics-based approaches may not accurately describe the time-varying wear process due to a lack of knowledge for underlying physics and simplifications involved in physical models, while the data-driven methods may be easily affected by the quantity and quality of data. To overcome the drawbacks of these two approaches, a hybrid prognostics framework considering tool wear state is developed to achieve an accurate prediction. Firstly, the mapping relationship between the sensor signal and tool wear is established by support vector regression (SVR). Then, the tool wear statuses are recognized by support vector machine (SVM) and the results are put into a Bayesian framework as prior information. Thirdly, based on the constructed Bayesian framework, parameters of the tool wear model are updated iteratively by the sliding time window and particle filter algorithm. Finally, the tool wear state space and RUL can be predicted accordingly using the updating tool wear model. The validity of the proposed method is demonstrated by a high-speed machine tool experiment. The results show that the presented approach can effectively reduce the uncertainty of tool wear state estimation and improve the accuracy of RUL prediction.


2021 ◽  
Author(s):  
Hüseyin Gürbüz ◽  
Şehmus Baday

Abstract Although Inconel 718 is an important material for modern aircraft and aerospace, it is a kind material, which is known to have low machinability. Especially, while these types of materials are machined, high cutting temperatures, BUE on cutting tool, high cutting forces and work hardening occur. Therefore, in recent years, instead of producing new cutting tools that can withstand these difficult conditions, cryogenic process, which is a heat treatment method to increase the wear resistance and hardness of the cutting tool, has been applied. In this experimental study, feed force, surface roughness, vibration, cutting tool wear, hardness and abrasive wear values that occurred as a result of milling of Inconel 718 material by means of cryogenically treated and untreated cutting tools were investigated. Three different cutting speeds (35-45-55 m/min) and three different feed rates (0.02-0.03-0.04 mm/tooth) at constant depth of cut (0.2 mm) were used as cutting parameters in the experiments. As a result of the experiments, lower feed forces, surface roughness, vibration and cutting tool wear were obtained with cryogenically treated cutting tools. As the feed rate and cutting speed were increased, it was seen that surface roughness, vibration and feed force values increased. At the end of the experiments, it was established that there was a significant relation between vibration and surface roughness. However, there appeared an inverse proportion between abrasive wear and hardness values. While BUE did not occur during cryogenically treated cutting tools, it was observed that BUE occurred in cutting tools which were not cryogenically treated.


Author(s):  
David Stock ◽  
Aditi Mukhopadhyay ◽  
Rob Potter ◽  
Andy Henderson

Abstract This paper presents the analysis of data collected using the MTConnect protocol from a lathe with a Computer Numerical Control (CNC). The purpose of the analysis is to determine an estimated cutting tool life and generate a model for calculating a real-time proxy of cutting tool wear. Various streams were used like spindle load, NC program blocks, the mode, execution etc. The novelty of this approach is that no information about the machining process, beyond the data provided by the machine, was necessary to determine the tool’s expected life. This method relies on the facts that a) it is generally accepted cutting loads increase with tool wear and b) that many CNC machines rely on a small set of regularly run CNC programs. These facts are leveraged to extract the total load for each run of each program on the machine, creating a dataset which is a good indicator of tool wear and replacement. The presented methodology has four key steps: extracting cycle metadata from the machine execution data; computing the integrated spindle loads for every cycle; normalizing the integrated spindle loads between different programs; extracting tool wear rates and changes from the resulting dataset. It is shown that the method can successfully extract the signature of tool wear under a common set of circumstances which are discussed in detail.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 623 ◽  
Author(s):  
Dervis Ozkan ◽  
Peter Panjan ◽  
Mustafa Sabri Gok ◽  
Abdullah Cahit Karaoglanli

Carbon fiber-reinforced polymers (CFRPs) have very good mechanical properties, such as extremely high tensile strength/weight ratios, tensile modulus/weight ratios, and high strengths. CFRP composites need to be machined with a suitable cutting tool; otherwise, the machining quality may be reduced, and failures often occur. However, as a result of the high hardness and low thermal conductivity of CFRPs, the cutting tools used in the milling process of these materials complete their lifetime in a short cycle, due to especially abrasive wear and related failure mechanisms. As a result of tool wear, some problems, such as delamination, fiber breakage, uncut fiber and thermal damage, emerge in CFRP composite under working conditions. As one of the main failure mechanisms emerging in the milling of CFRPs, delamination is primarily affected by the cutting tool material and geometry, machining parameters, and the dynamic loads arising during the machining process. Dynamic loads can lead to the breakage and/or wear of cutting tools in the milling of difficult-to-machine CFRPs. The present research was carried out to understand the influence of different machining parameters on tool abrasion, and the work piece damage mechanisms during CFRP milling are experimentally investigated. For this purpose, cutting tests were carried out using a (Physical Vapor Deposition) PVD-coated single layer TiAlN and TiN carbide tool, and the abrasion behavior of the coated tool was investigated under dry machining. To understand the wear process, scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) was used. As a result of the experiments, it was determined that the hard and abrasive structure of the carbon fibers caused flank wear on TiAlN- and TiN-coated cutting tools. The best machining parameters in terms of the delamination damage of the CFRP composite were obtained at high cutting speeds and low feed rates. It was found that the higher wear values were observed at the TiAlN-coated tool, at the feed rate of 0.05 mm/tooth.


2012 ◽  
Vol 201-202 ◽  
pp. 1178-1181
Author(s):  
Guo Bing Chai ◽  
Wei Wang ◽  
Ai Bing Yu

Edge preparation is not only the process of grinding proper geometry of cutting edge or removing micro-cracks on cutting edge region, but also a way of improving cutting tool life. In this study, cutting models with different cutting edge radius were set up with FEM software. Medium carbon steel cutting tests were carried out using cutting tools with different edge radius. Cutting tool wear was simulated and measured for comparison. The simulation results show that edge radius has influences on tool wear. Tool cutting behavior is concerned with edge radius. A proper edge radius will improve the tool life. The experimental results show that proper edge preparation could improve tool impact resistance capability and reduce tool wear. The cutting tool life can be prolonged with suitable edge preparation. Edge preparation can improve cutting performance of cutting tool.


1969 ◽  
Vol 91 (3) ◽  
pp. 790-796 ◽  
Author(s):  
A. Bhattacharyya ◽  
I. Ham

Cutting tools of sufficient strength against failure by brittle fracture or loss of “form stability” through rise of interface temperatures, still continue to fail by a process of “wear,” which is loss of cutting tool material through gradual interaction between the work and the tool material. Such wear can take place either at the principal flank surface or at the top face of the cutting tool for roughing and semiroughing cuts. Wear may also occur at the auxiliary flank surface resulting in grooving wear during fine machining or machining of high strength materials. The causes for such wear processes include (i) mechanical interaction (abrasion or adhesion and transfer type), (ii) thermochemical interaction (diffusion or chemical reaction). As a part of this investigation on tool wear, two theoretical models have been proposed for explaining mechanical wear at the flank surface. These models explain the nature and characteristics of wear growth and the sensitiveness and dependence of interaction phenomena between the tool-work pair.


Symmetry ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 296 ◽  
Author(s):  
Ovidiu Moldovan ◽  
Simona Dzitac ◽  
Ioan Moga ◽  
Tiberiu Vesselenyi ◽  
Ioan Dzitac

2015 ◽  
Vol 798 ◽  
pp. 372-376
Author(s):  
Tadahiro Wada

As high silicon aluminum alloys have both a high strength-to-weight ratio and good wear-resistance, they are used for many automobile and motorbike parts. High silicon aluminum alloys are generally machined to improve dimensional accuracy. In cutting high silicon aluminum alloys such as Al-17mass%Si alloy, the primary Si particles have a negative influence on tool wear. Therefore, polycrystalline diamond compact cutting tools are widely used. In this study, in order to improve the tool wear resistance of polycrystalline diamond compact cutting tools, the Si particle size of Al-17 mass% Si alloy was changed by adjusting the water-cooling speed. Two different kinds of Si particle size, which were changed by adjusting the water-cooling speed, were used. The Al-17mass%Si alloy was turned with the polycrystalline diamond compact cutting tool and the tool wear was experimentally investigated. The main results were as follows: (1) The formed Si particle size was from 30 to 70 μm or from 40 to 170 μm. (2) The mechanical properties of the Al-17 mass% Si alloy did not depend on the Si particle size. (3) The Si particle size included in the Al-17 mass% Si alloy had a major influence of the tool wear, and it was possible to reduce the tool wear by increasing the Si particle size including that in the Al-17 mass% Si alloy.


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