Papers by Keyword: Cutting Fluids

Abstract: During a machining operation, the tool tip is subjected to elevated interface temperatures and contact pressures. A considerable improvement can be achieved through an appropriate selection and application of a cutting fluid. Although many technologies attempt to reduce their use to move to a cleaner production, they are still widely employed in industry. Under such severe conditions, it is necessary to understand their exact contribution from a tribological point of view in order to optimize their use. The aim of this study is to evaluate the ability of a fluid to penetrate and remain at the tool-material interface.

Abstract: In recent years, hybrid manufacturing combining additive and subtractive processes is gaining increasingly importance in the industry. One of the issues related to this association of processes concerns the use of cutting fluids, important to optimize the machining part, but that can strongly affect the additive part by generating pores in the laser metal deposition. The present work deals with the performance of a new ecological cutting fluid that dries just as water, eliminating the need for a cleaning step between the machining and the laser metal deposition. This lubricant is an emulsion mainly composed of water and alkylphosphonic acids known to allow creating a low-friction tribofilm on metals. This study is carried out by comparing the machining performance of this new cutting fluid with two more classical lubricants, a straight oil and a soluble oil. It was found that machining forces and surface roughness were not very affected by the change of the lubrication mode, while the tool wear showed a significant difference between the dry and the lubricated cases. Considering that the performance of all the cutting fluids was very close, it was concluded that the new lubricant has a great potential for machining applications, since it is ecologically more friendly, non-harmful to the operator and does not need a degreasing step.

Abstract: Conventional cutting fluids are known for being expensive, polluting and a non-sustainable part of modern manufacturing processes. Global industrial trends are leaning towards environmental and health friendly technologies. CO2 cooling is an innovative and sustainable method, capable of replacing conventional oil-based cutting fluids under various conditions. The current study intends to cover the indexable insert drilling of aluminium-silicon carbide (Al-SiC) metal matrix composite (MMC) using different diamond coated carbide inserts. Al-SiC composite containing 20% wt. of SiC was used as workpiece material under different cooling strategies. Response Surface Methodology (RSM) and SEM analysis were incorporated to evaluate the tool performance and to understand the wear development in drilling of MMC. Performance tests were carried out at various cutting data and cooling strategies (external CO2, external emulsion, internal CO2 and internal emulsion) in order to study the output in terms of tool life, surface finish and diameter difference of the holes. The results revealed an advantage in the favour of CO2 cooling concerning tool life, precision and surface finish. Drilling with internal supply of CO2 significantly improves the tool life. The internal supply of CO2 generated the best precision and surface finish compared to the other cooling strategies. The test results clearly indicate that the tool failure for internal CO2 is governed by the flaking of the diamond coating in contrast to a combination of flank wear and flaking for emulsion. The results from the external cooling strategy show that there is no significant difference between emulsion and CO2 while the internal cooling strategy shows that CO2 provides the best results. Since the shape and the surface of the hole are generated by the cutting edge of the periphery insert, the wear development on the periphery insert is the main factor which governs the tool life, surface finish and the diameter difference. This can be explained by the internal CO2 strategy that protects the periphery insert.

Abstract: In modern machining processes, there are continuous cost pressures and high quality expectations in the product. Hence, it is required to explore the techniques that can reduce the cost and also increase the quality of the product. In the present work, machining performance of AISI 316L SS is assessed by the performing turning operation under nano cutting environment. Experiments have been carried out by plain turning of 48mm diameter and 600mm long rod of AISI 316L stainless steel on all geared lathe at different cutting velocities and feeds under wet machining with and without Carbon nano Tubes (CNT) inclusions using carbide inserts. The effect of cutting speed, feed rate, depth of cut on tool chip interface temperature and surface roughness are analysed using Taguchi method. Furthermore, using analysis of variance method, significant contributions of process parameters have been determined. Experimental results reveal that feed rate and cutting speed are the dominant variables on responses.

Abstract: The increase in pollution and contamination of the environment in recent years has resulted in the increase of interest in its protection. The basic premise of environmental policy, which is reflected in a number of legal acts, is carrying out activities aimed at minimizing the amount of produced waste [1-3]. In particular, this applies to waste that have harmful effects on the environment, and it includes the vast majority of industrial oils and technological, petroleum-based fluids (over 85%) [4]. One of the fundamental directions related to their use, in accordance with the standards of protection of the environment, is reducing the consumption by extending their functional life [5]. The maximum extension of the functional life for oils and fluids is the goal of the systemic approach to the problem of rational use, which includes the process of the monitoring of key functional properties and systematic, periodical treatment. The most beneficial are on-site treatment processes of oils and fluids conducted while maintaining the continuity of the technological processes. It is preferable to use mobile treatment devices, which provide the means to create a dispersed system in fluid treatment in successive machines and equipment [6-8].

Abstract: The use of cutting fluids in turning can change thermomechanical loading of cutting tools. Currently, manufacturers provide a wide range of cutting fluids, which have different combinations of lubricating and cooling properties. Depending on cutting conditions, this combination can reduce tool wear in different degrees, and, in some cases, to even increase it. Therefore, an effective choice of cutting fluids requires a considerable amount of experiments, which requires cost and time. To solve this problem in the software SIMULIA/Abaqus Explicit 6.10 was developed thermomechanical model of the turning process by cutting tools with PVD-coating, which allows simulating the effect of any combination of cooling and lubricating action. An Arbitrary Lagrangian-Eulerian formulation method was used in the modeling. Under the lubricating and cooling action is understood the final result of interaction of cutting fluids with the cutting zone. Modeling of lubricating action of cutting fluid is performed by introducing into the model corresponding average coefficient of friction in the contact zone of cutting tool, worked material and cutting fluid. Modeling of cooling action of cutting fluids is implemented through the introduction of the heat transfer coefficient, calculated on the basis of cutting conditions and thermo-physical properties of cutting fluids. As an example, turning of austenitic stainless steel X10CrNiTi18 by carbide cutting insert with TiN-coating for a predetermined cutting condition was examined. A selection of cutting fluids of the proposed range, formulations of which have different combinations of cooling and lubricating properties ("Unizor-M", "Ferrobetol-M", "EkoEM-1", "STARCUT E9", "SAFECUT M120") was accomplished through the simulation model and the calculated data contact stresses. Experimental studies have confirmed the validity of this choice by comparing the rate of flank tool wear in the using different cutting fluids. The rate of wear was determined by surface micrographs of flank tool. An application of the recommended cutting fluid "SAFECUT M120" has reduced wear by 4 times as compared with the application of the "Ferrobetol-M", the use of which has shown the highest wear. The model developed can be used for selecting a predetermined range of cutting fluids, in determining the optimal combination of lubricating and cooling actions for establishing the required characteristics of cutting fluid or in developing new formulations of cutting fluids.

Abstract: The use of cutting fluid is to reduce the friction between tool and workpiece, reduce and dissipate generated heat. The application of cutting fluid is also to improve the surface quality of workpiece and increase the tool life. On the other side, cutting fluid contains chemical carcinogens that causes serious health risks for machine operators and have inherent waste disposal concern on the environment. Due to these problems, some alternative have been sought to minimize or avoid the use of cutting fluid in machining processes. Air cooling techniques were proposed as alternative cooling mediums, i.e air jet cooling (AJC) and cooled-air jet cooling (CAJC), the liquid less method. In this work, air cooling techniques were investigated to be a possible solution of machining problem for cooling medium. This studi was also motivated by economics point of view that the application of AJC and CAJC would be more efficient than liquid method. The purpose of this study is to investigate the effect of AJC and CAJC on turning process of St 60 steel because it is used widely for production of components especially in small and medium enterprises in Indonesia. The tool tip temperatures, surface roughness and tool wear were measured for a range of cutting times. For a comparison purposes, experiments were also carried out with using traditional liquid coolant and without any cooling applied to the tool tip (dry cutting method). Experiments have shown that air cooling technques (AJC, and CAJC) can be used as cooling medium in machining process. Experimental results show that machining with CAJC have shorter tool life compare to machining with AJC and dry cutting, but liquid coolant in this studi is still the best cooling medium for machining of St 60 steel..

Abstract: Green manufacturing is a method in which products are produced by consuming less energy and natural resources and being safe to employees, consumers, environment and society. This paper presents an experimental study that compares the machining characteristics when a soy-based cutting fluid and petroleum-based alternate are used in turning medium and high carbon alloy steels. The result of the study will provide reference for cutting fluid management personnel to make proper decision to substitute traditional cutting fluids with the environment-friendly product.