Tool life

Influence of cooling fluid application on the tool wear, during longitudinal turning of hardened chrome nickel steel, on the basis of experimental investigations is presented in this paper. Cutting tool wear investigation through comparation dry machining and machining by cooling fluid application, for the same other machining conditions, are conducted. Tool wear size, tool wear shape and cutting tool life are taken into account by cutting tool wear investigation. Analysis of experimental results showed inverse proportion between coolig fluid application and flank wear size, as well as significance of influence on tool wear and its characteristics, via the flank wear shape. Also, analysis of experimental results showed significance of influence coolig fluid application on increase of cutting tool life.

This paper presents an approach, for the systematic design of condition monitoring system for machine tool and machining operations. The research is based on utilising the genetic optimization method for the on-line optimization of the cutting parameters and to design a programme for the signal processing and for the detection of fault conditions for milling processes. Cutting parameters and the measured cutting forces are selected in this work as an application of the proposed approach.

Cryogenic treatment is a thermal treatment process in which parts are usually cooled to temperatures below −70 °C (< 203 K) to induce metallurgical changes in materials. The treatment showed a significant performance improvement in most ferrous materials and their alloys by transforming retained austenite to martensite and precipitating secondary carbides. However, the effect of such low-temperature treatment on highly stable super-hard materials such as tungsten carbide (commonly referred to as “cemented carbide”) is uncertain. However, researchers have reported the precipitation of etaphase carbides, densification of cobalt binder, refinement of tungsten carbide grains, phase transformation of cobalt, and changes in residual stress in cryogenically treated tungsten carbide (WC-Co) materials, which resulted in increased hardness and wear resistance. Hence, this paper focuses on summarizing the cryogenic treatment parameters used in different studies, the rate of performance improvement in different applications, and the reported mechanical and metallurgical changes, which would serve as a pool of knowledge for further studies.

Improvement in wear resistance and hardness of cutting tool material is one of the most important challenges in machining operation. This issue can be overcome by improving the wear resistance and hardness by cryogenic treatment of tungsten carbide. In this work it is tried to study the effect of different soaking periods in cryogenic treatment of tungsten carbide. The experiments were conducted at temperature of 88K at different soaking periods of 8hrs, 20hrs, 24hrs and 30hrs, on commercially used tungsten carbide. Further efforts were made to quantify and confirm the effect of different soaking period along with the mechanism responsible for change in the hardness and wear resistance by measuring Rockwell hardness and weight loss during wear test. The obtained result shows that there is a significant decrease in weight loss of 8hr soaked sample out of different soaking periods but, there was no change in bulk hardness. The weight loss during sliding wear test indicates the cryogenically treated tungsten carbide is more wear resistance due to increase in population density of carbides. Microstructure analysis of worn surface reflects the mechanism behind the improvement of mechanical properties.

Abstract: This paper presents the suitable depth of cut, spindle speed and feed rate that will be chosen during machining. If thus parameters are not considered, this can provoke abnormal tool behavior such as chatter. Chatter will limit the tool life which only can be use for just a ...

Current experimental studies have yielded that cutting speed, using carbide cutters, has no significant influence on surface roughness obtained for machining the α-β Titanium alloy Ti-6Al-4V. This paper presents results of experimental investigations carried out on the widely used titanium alloy Ti-6Al-4V using variable cutting speeds as well as different cutting tools at a constant feed rate and depth of cut. The effects of varying cutting speeds on the tool life have been analysed by inspecting the surface roughness of the machined samples and the tool wear observed during machining. As the cutting speed increases, the tool life drops off very rapidly and at higher cutting speed the chips start to ignite because of high heat generation at the cutting zone which is mainly caused by the low thermal conductivity of titanium alloys as postulated. Consequently higher cutting speeds may be used to dramatically reduce the production costs, but the currently available cutting tools will h...

The purpose of this work is to investigate flank wear and productivity of cutting tools in machining X38CrMoV5-1 treated at 50 HRC. This steel is intended for hot work and free from tungsten on CrMoV basis. It is employed for the manufacture of moulds, module matrices of door for car and helicopter rotor blades. The tests of straight turning were carried out under dry conditions using the following tools: uncoated carbide (H13A), coated carbide (GC3015), mixed ceramic (CC650), whisker ceramic (CC670), uncoated cermets (CT5015) and coated cermets (GC1525). Experimental results enable us to study the influence of chip machining length on flank wear VB of these tools for two different cutting regimes. The results indicate that mixed ceramic (Al 2 O 3 +TiC) is more efficient than other grades used in terms of wear resistance and productivity. Consequently, it is the most powerful.

As organizacoes atualmente estao enfrentando uma nova economia globalizada motivada por desafios cada vez mais exigentes. Hoje, seus concorrentes podem estar em qualquer lugar do planeta e a sobrevivencia no mercado esta condicionada a melhoria continua da fabricacao de seus produtos e prestacao de servicos. Neste contexto de extrema concorrencia, as organizacoes utilizam cada vez mais diferentes metodologias, abordagens e ferramentas estatisticas para melhoria continua de seus processos. Este artigo utiliza a metodologia do ciclo Plan-Do-Check-Act (PDCA) no processo de automatizacao de uma fresadora numa industria do setor metal mecânico da regiao norte do estado de Santa Catarina. Para aplicacao correta desta metodologia as ferramentas de analise e de melhoria continua sao formatadas e adaptadas de acordo com a necessidade e demandas da equipe, atraves da coleta de dados, analise dos casos, implementacao de acoes e monitoramento de todo o processo de automatizacao. Os resultados d...

Chatter is a self-excited vibration which occurs in milling machines while operating at high speed. This is an undesirable phenomenon which has negative effects, such as poor surface finish, unacceptable accuracy, excess noise, tool wear and lower Material Removal Rate (MRR). Chatter is self-excited vibration which can occur by various phenomenon’s like Frictional chatter, thermo-mechanical chatter, Mode Coupling Chatter and very importantly regenerative chatter. Prediction and detection of chatter is very important in milling machine tool, which gives guidance to the machine tool user for an optimal selection of depth of cut and spindle speed, which results in higher material removal rate with high accuracy, with less vibrations. Chatter prediction is very complicated phenomenon in machine for its avoidance. In this paper, various methods are presented for the prediction of chatter. Analytical and experimental methods are presented in this paper for the chatter control which gives ...

The work carried out was on a special purpose grinding CNC machine-Meccanodora Cimat C-661, a 3axis PCbasedCNCcontrollerhavingmaximumspeedof40,000RPM.WhentheprojecttomodifytheCIMA TC-661ID grinder CNC machine tool was proposed, the machine tool, process and modification plan were studied. The company's requirement was to grind the inner surface of the rotary sleeve valve in the ID grinder to a very high surface finish (0.5-0.6 Microns) and high precision, so a new ID grinder CNC was needed. As the new machine would be too expensive, the company considered modifying the existing ID grinding C-661CNC to a general-purpose ID grinding CNC, which makes itcost-effectiveandsuitableforgrindingrotarysleevevalvesand othercylindricalparts.Aspecialfixturedesignwas requiredfor holding the sleeve valve that would serve the requirement. Therefore, a collet type of fixture was designed which will self-lock the sleeve valve with the existing setup. The designed automatic clamping system with collet fixture reduced human intervention which were often prone to errors. Therefore, considering all the design aspect, the special purpose magnetic type of fixture made up ofchrome vanadium alloy spring steel 0.50%C was replaced with a collet type offixture.Thisinturn hasfoundtoreducethetotal costfornewmachine providingmaximum benefitsintermsof company and customer.

The objective of the research presented in this paper is to characterize the machinability of TOOLOX 44 during cutting with PALBIT inserts with focus on how different combinations of coatings and substrates influence the machining process in aspects such as tool life, cutting forces, temperature and chip forming process. The foremost result is that TOOLOX is machinable and when the right tool is chosen high productivity can be achieved. Using the right insert, equipped with chip-breaker, should allow to machine this hardened steel even at higher cutting speeds than the ones used in this investigation.

This study used AA8011 High Speed Milling and Solid Carbide End Mill cutting tools to examine the influence of several cutting parameters, namely cutting speed, feed rate, and depth of cut, on the ultimate performance attributes, specifically surface roughness. An analysis will be conducted using Taguchi's L9 orthogonal array and ANOVA to examine the collective effects of the process parameter on two presentation features. The data suggest that feed rate and cutting speed may effectively manage surface roughness. Nevertheless, the depth of cut is the paramount factor in determining the feed rate. The empirical data was then subjected to multiple linear regression analysis in order to ascertain the allowable range of surface roughness and establish a correlation between cutting parameters and performance characteristics. The examination of the machined surface of the tool workpiece was conducted using both an optical microscope and a scanning electron microscope (SEM), while adhering to optimal cutting conditions (vs = 450 m/min, ft = 0.1 mm/rev, and dc = 0.25 mm