Methods of Considering Reliability in the Quality Evaluation Procedure for Composite Metal Cutting Tools

2015 ◽  
Vol 770 ◽  
pp. 216-220 ◽  
Author(s):  
E.V. Artamonov ◽  
D.S. Vasilega ◽  
M.S. Ostapenko

In terms of method for evaluating the quality of composite metal cutting tools, a need to regard reliability as a factor, consisting of several components, is grounded. It is discovered, that thermal compatibility of processed material and material of the tool, has a significant impact on composite cutters’ durability. So does the force of stress, created in the cutting edge. In order to take all these factors into account when evaluating the quality of metal cutting tools, the need to include stress and thermal compatibility coefficients has been proven. Means to determine the attributes needed and formulas for calculation of those coefficients had been developed. The methods we created can be used for the evaluation of both the existing tools and for the perspective tools currently being developed.

2020 ◽  
Vol 405 ◽  
pp. 240-244
Author(s):  
Atila Drotár ◽  
Pavol Zubko ◽  
Alicia Mašlejová ◽  
Peter Kalmár ◽  
Peter Vranec ◽  
...  

Introduction of new technologies demands a new access to quality evaluation of products. Joining of steel sheets with laser butt welding requires increased demand on precision of welded sheet ends alignment as well as condition of cutting edge. Moreover, increased requirements are placed on purity of environment, flatness of strips, gases, etc. The paper deals with evaluation of quality of laser butt welds of steel sheets and description of defects which could occur on welds from the metallographic point of view. The influence of relative displacement of welded strips ends alignment, different relative sheet thickness alignment, welding gap size and quality of sheet shear edge on quality of weld will be described. The most significant effect on quality of weld joints and their final mechanical properties has relative position of strip ends and geometry of cutting edge.


Author(s):  
Salman Pervaiz ◽  
Sathish Kannan ◽  
Wael Abdel Samad

In machining operation, cutting tool performs a central role towards the overall machining performance. A user from metal cutting community always look for better cutting tools that can enhance productivity by reducing tool wear and cost. Modification in the micro-geometry of cutting edge is termed as edge preparation, and it is performed to improve the machining performance by strengthening the cutting edge, reducing internal stresses of coating and lowering the edge chipping etc. Edge preparation has a controlling influence on the formation of deformation zones, cutting temperature, cutting forces and stresses at the cutting interface. Vibration assisted machining (VAM) concept is gaining fame in the metal cutting sector community for machining difficult-to-machine materials. In VAM, cutting tool moves with a small amplitude vibration instead of moving with a constant cutting velocity. This small amplitude vibrational movement provides better machining performance for difficult-to-cut brittle materials. The current numerical study utilized different edge prepared micro-geometries such as sharp edge, round edge and chamfer edge etc. cutting tools, and then these cutting tools were used in the numerical simulations of VAM. The study shows higher magnitude of cutting forces under VAM with tools with modified geometry. The study is beneficial for the metal cutting community and opens new areas of industrial applications.


2009 ◽  
Vol 618-619 ◽  
pp. 117-126 ◽  
Author(s):  
E. Derry Doyle ◽  
S.J. Dowey

Advances have been made in the art of metal cutting, much to the economic benefit of industrialized nations. Not withstanding this, engineers continue to seek stronger and lighter materials. New challenges emerge as we seek to understand and control the deformation of a small volume of material in the immediate vicinity of the cutting edge. In this paper we use a metallurgical approach to explore and understand the nature of high strain deformation in light metals and its influence on the chip forming process. In particular the phenomenology of material flow around the cutting edge is discussed on the basis of previous studies of machining in the SEM. The issue of chip separation is discussed, particularly in relation to its impact on the tribology of the ship / tool / workpiece interface. The objective is to better design cutting tools and their vapour deposited coatings for improved machinability in light metals.


2016 ◽  
Vol 1815 ◽  
Author(s):  
John Henry Navarro Devia ◽  
Willian Aperador Chaparro ◽  
Jairo Cortes Lizarazo

ABSTRACTThe main purpose of coatings is to increase the lifetime of cutting tools, to perform continuous and economical material removal process, reducing the frequency of sharpening or replacement of the tool, which contributes to increase quality of product. Therefore, hafnium nitride (HfN) single layer coatings were deposited on High-speed steel by Magnetron Sputtering physical vapour deposition (PVD). The machining on AISI 1020 steel samples were carried out in a computer numerical control (CNC) machine, using coated and uncoated tools, the temperature of the different components were measured (steel bar and tool), due to continuous temperature measurement help to predict tool wear and the quality of finished piece [1] . In order to evaluate wear resistance and performance, not only temperature data were compared, the tool wear morphological analysis for flank wear was carried using Scanning Electron Microscopy (SEM), and work pieces roughness were checked through their surfaces in an Atomic Force Microscopy (AFM). In most of the parameters evaluated differences between the tools were identified, and results reveals that on HfN coating, occurs less wear, due the proportionality between the energy transfer and the tool deterioration, also the coating improves surface finish of the machined part; all of them are reflected in changes on process temperatures. The use of single layer HfN coating on cutting tools could increase their lifetime, improve the quality of the work piece, and even reduce process time and cost.


2018 ◽  
Vol 224 ◽  
pp. 01003
Author(s):  
Vladimir Bogutsky ◽  
Yurij Novoselov ◽  
Leonid Shron

The article shows that during the grinding of complex profile blades of metal cutting tools from tool steels, unfavorable thermodynamic conditions are created in the cutting zone and, as a result, grinding burns and cracks occur on the surface of the polished workpiece. One of the methods of controlling the temperature in the cutting zone at the final grinding operations is the use of grinding wheels with a discontinuous surface. The method of calculating the profile of the discontinuous surface of the grinding wheel presented in the article makes it possible to determine its geometric parameters taking into account the wear resistance of the grinding wheel and the heat stress of the process of treatment. The results of the verification of the proposed technique in the production conditions are given which showed that the treatment of the teeth of the broaches with a grinding wheel with a discontinuous profile, in comparison with the machining of broaches according to the traditional technology, provides a higher quality of blade surfaces, while the process productivity, compared with the factory technology, increased by 20...26%.


Author(s):  
Б.Я. Мокрицкий ◽  
В.М. Давыдов

Актуальность. Изложены результаты совершенствования токарной обработки заготовок ответственных деталей морских судов, особенно подводных, и сооружений, подвергаемых в процессе эксплуатации агрессивному воздействию морской воды, например, валопроводов судов. Такие детали, как правило, выполняются из специализированных труднообрабатываемых нержавеющих сталей. Специфические свойства таких сталей создают серьёзные сложности при их обработке лезвийным металлорежущим инструментом. Например, период стойкости типового токарного резца отечественных или зарубежных изготовителей не превышает 40 минут. Это не приемлемо для сегодняшнего уровня высокопроизводительной обработки. Целью работы является повышение эффективности токарной обработки таких сталей. Решение этой задачи достигнуто за счёт разработки новых покрытий для таких режущих пластин. Методы исследования. Для разработки использовано имитационное моделирование как метод исследования. Оно выполнено в программной среде Deform. Она адаптирована под решаемую задачу. Результаты. Разработан металлорежущий инструмент с покрытиями, обеспечивающий повышение периода стойкости в 2 и более раз. Вывод. Поставленная цель достигнута. Обеспечено повышение периода стойкости металлорежущего инструмента в 2 и более раз без снижения производительности обработки и с повышением качества поверхности обработанной заготовки детали. The relevance of the research is due to the fact, that a number of parts of marine vessels and structures must be made of corrosion-resistant steels. These are specialized stainless steels. They have a lot of chrome and nickel. It makes difficult to process blanks of details by metal-cutting tools. Its durability period is insufficient. The aim of the research is to increase the efficiency of turning such steels. Efficiency here means an increasing of the service life of a metal-cutting tool without decreasing of the processing performance and the quality of the machined surface of the detail. The software environment Deform was used as a method of the simulation research. Initial and output criterias have been developed for it. For this purpose, the software environment is adapted to the solving problem. As input parameters, the architecture of the coating is set, when applied to the hard-alloy material, an increase of the tool life is expected. The following results were obtained. Coatings for turning tools, providing the increase of the tool life to 2 or more times, were designed. The output. The setted goal has been achieved. The service life of the metal-cutting tool is increased to 2 or more times without decreasing of the processing performance and with an increase of the surface quality of the processed details.


1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.


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