Cutting Fluid Emulsion Research Articles

Cutting fluid role in the machinability of AZ91/SiC composite: Tool wear and surface roughness

Metal matrix composites (MMC) introduced special features such as resistance to wear and high strength to weight ratio and these characteristics categorized them as difficult-to-cut materials in the field of machining. In the current paper, a novel study on the cutting fluid emulsion 5% role in the machinability of a magnesium-based metal matrix composite reinforced by silicon carbide (SiC) particles is presented. AZ91 magnesium alloy, with nominal composition Mg-9Al-1Zn, composites were made using stir casting method. Then, the composite samples were machined and the cutting parameters such as cutting speed, feed rate and side cutting edge angle were varied to assess their effects on the wear and surface roughness. To measure and analyze the wear, optical and scanning electron microscope (SEM) were used. Also, elemental analysis through energy-dispersive X-ray spectroscopy (EDS) was accomplished. Surface roughness of machined samples were measured by a profilometer and 3D surface topography. Results of SEM and EDS images indicated that SiC particles included in the composites act as grinders and remove the surface of tool even in a short time because of the severe abrasion. Additionally, surface of machined MMCs contains some defects such as cracks, broken SiC, and unwanted deformations. Using cutting fluid emulsion 5% enhanced the tool life as well as the surface quality remarkably for different cutting speeds, feed rates and cutting edge angles although finished surface of the samples were oxidized. Also, the cutting fluid considerably reduced the amount of adhered materials on the flank face.

Novel Hydrophobic Ultrafiltration Membranes for Treatment of Oil-Contaminated Wastewater

Cutting fluids are the main source of oily wastewater in the metalworking industry. This study deals with the development of antifouling composite hydrophobic membranes for treatment of oily wastewater. The novelty of this study is that a low energy electron-beam deposition technique was applied for a polysulfone (PSf) membrane with a molecular-weight cut-off of 300 kDa, which is promising for use in the treatment of oil-contaminated wastewater, by using polytetrafluoroethylene (PTFE) as target materials. The effect of the thickness of the PTFE layer (45, 660, and 1350 nm) on the structure, composition, and hydrophilicity of membranes was investigated using scanning electron microscopy, water contact angle (WCA) measurements, atomic force microscopy, and FTIR-spectroscopy. The separation and antifouling performance of the reference and modified membranes were evaluated during ultrafiltration of cutting fluid emulsions. It was found that the increase in the PTFE layer thickness results in the significant increase in WCA (from 56° up to 110-123° for the reference and modified membranes respectively) and decrease in surface roughness. It was found that cutting fluid emulsion flux of modified membranes was similar to the flux of the reference PSf-membrane (7.5-12.4 L·m-2·h-1 at 6 bar) while cutting fluid rejection (RCF) of modified membranes increased compared to the reference membrane (RCF = 58.4-93.3% for modified and RCF = 13% for the reference PSf membrane). It was established that despite the similar flux of cutting fluid emulsion, modified membranes demonstrate 5-6.5 times higher flux recovery ratio (FRR) compared to the reference membrane. The developed hydrophobic membranes were found to be highly efficient in oily wastewater treatment.

Adsorption Soluble Cutting Fluid Emulsion by Modified Chitosan with SLES

Adsorption Soluble Cutting Fluid Emulsion by Modified Chitosan with SLES

Comparison of CNT-PVA membrane and commercial polymeric membranes in treatment of emulsified oily wastewater

Membrane separation is an attractive technique for removal of emulsified oily wastewater. However, polymeric membranes which dominate the current market usually suffer from severe membrane fouling. Therefore, membranes with high fouling resistance are imperative to treat emulsified oily wastewater. In this study, carbon nanotube-polyvinyl alcohol (CNT-PVA) membrane was fabricated. And its separation performance for emulsified oily wastewater was compared with two commercial polymeric membranes (PVDF membrane and PES membrane) by filtration of two homemade emulsions and one cutting fluid emulsion. The results show that these membranes have similar oil retention efficiencies for the three emulsions. Whereas, the permeation flux of CNT-PVA membrane is 1.60 to 3.09 times of PVDF membrane and 1.41 to 11.4 times of PES membrane, respectively. Moreover, after five consecutive operation circles of filtration process and back flush, CNT-PVA membrane can recover 62.3% to 72.9% of its initial pure water flux. However, the pure water flux recovery rates are only 24.1% to 35.3% for PVDF membrane and 6.0% to 26.3% for PES membrane, respectively. Therefore, CNT-PVA membrane are more resistant to oil fouling compared with the two polymeric membranes, showing superior potential in treatment of emulsified oily wastewater.

Hard machining performance of indigenously developed green cutting fluid using flood cooling and minimum quantity cutting fluid

Cutting fluids play a vital part in turning process. Basically, these cutting fluids are made up of mineral oil (MO) and performance enhancing additives that are produced chemically. However, MO has adverse environmental effects and causes health hazards. Therefore, MO is gradually replaced by green cutting fluid (GCF). Indigenously developed environmental friendly vegetable based GCF with minimum quantity cutting fluid (MQCF) application technique can serve as a viable solution to make current work a cleaner process. In this present study, vegetable-based GCF was synthesised and characterized. Emulsion stability and anti-corrosion properties of GCF were investigated. MQCF machining process parameters such as cutting fluid emulsion composition, nozzle stand-off distance and nozzle spray angle were experimentally optimized to extract better output. Hard machining experiments were performed with developed GCF using flood cooling (FC) and MQCF techniques during turning of hardened AISI H-13 steel. For comparison, dry machining experiments were also carried out. Cutting force, feed forces, centre line average (CLA) surface roughness of workpiece were measured and the coefficient of friction was calculated. After machining, cutting tool rake face morphology and wear characteristics were studied using field emission scanning electron microscope, optical microscope and non-contact 3D surface profilometer. Result shows that cutting force, feed force, coefficient of friction and CLA surface roughness of workpiece were reduced using optimized MQCF process parameters. Also, machining performance was improved with MQCF technique using GCF as compared to flood cooling and dry machining.

Enhanced separation performance of carbon nanotube–polyvinyl alcohol composite membranes for emulsified oily wastewater treatment under electrical assistance

Abstract Membranes provide an effective solution to treat emulsified oily wastewater, but usually have inherent drawbacks: permeability and selectivity trade-off as well as serious membrane fouling. In this study, carbon nanotube-polyvinyl alcohol (CNT-PVA) composite membranes with high water flux and good electrical conductivity were fabricated and then served as cathode during the filtration of n-hexadecane-in-water emulsion (n-emulsion) and cutting fluid emulsion (c-emulsion) to improve the oil removal efficiency and alleviate membrane fouling. Results show that oil removal rates increase from 85.2% to 97.6% for n-emulsion and from 56.7% to 83.0% for c-emulsion after the application of −1.5 V. The permeation flux after an operation of 60 min with −1.5 V are 2.3 times and 2.2 times of those without potential for n-emulsion and c-emulsion, respectively. Additionally, less oil fouling can be observed from the SEM images of the membrane surface and fouling can be mitigated according to the analysis of fouling model. Cyclic voltammetry and zeta potential analysis demonstrate that electrostatic repulsion rather than electrochemical reactions is responsible for the enhanced oil removal rate and antifouling ability in the filtration process. Furthermore, the results of long term filtration with five runs indicate that the application of potential onto the membranes maintains remarkable stability in high oil removal rate and high flux recovery rate.

The Lubricity Analysis of Cutting Fluid Emulsions

The new generation of cutting fluids should have some characteristics, such as low toxicity and biodegradability. A bio-cutting fluid emulsion are an excellent option because they present those properties, as well as good mechanical performance. The present study aims to investigate the lubricity of O/W emulsions (cutting fluid emulsion), varying the concentration of anionic surfactant (1%, 2.5% and 5%) and epoxidized oil (5%, 10%, 15%, 20% e 25%). A sunflower oil was chemically modified by epoxidation reaction, then its viscosity, iodine and oxirane index, density, and acidity were characterized. The performances of the emulsions were evaluated using a tribometer HFRR (High Frequency Reciprocating Rig), under hydrodynamic lubrication conditions. The ball wear scars were analyzed using an optical microscopy. The results showed that a low concentration of surfactant promote friction and wear reduction. Based on the tribological performance, the emulsions with 5% and 10% of epoxidized oil are more suitable.

Analysis of dimple textured surfaces on cutting tools

This paper presents the exploratory study of dimple-structured surfaces on cutting tools to reduce the friction between chip and the tool rake face. The objective is to study the effects of dimple-structured surfaces to the interactions between the chip and structured tool. Carbide inserts rake face which was structured with hemi-spherical micro-dimples with two different patterns using ultra-short pulse laser. Machining experiments were performed using three different materials: medium carbon grade steel ANSI 1045, cast iron ANSI GGG40, and aluminum alloy ANSI 2024-T6. The experiments were performed, under different cutting speeds and feed rates, at a constant cutting depth, and using 10% cutting fluid emulsion. Reference experiments were conducted with non-structured tool, and the results were compared. The results show that the interactions between the chip and structured rake face depend on the chip formation. Continuous chips with high contact length can produce enough lift hydrodynamic force to induce a cutting force reduction. No significance reduction on the cutting forces was observed for lamellar-segmented and discontinuous chips. The cutting parameters and the concentration of dimples are also importance design factor to be considered.

Study of the effect of Vegetable oil based cutting fluid on machining characteristics of AISI 316L Steel

In the present work, properties of the non-ionic surfactants have been identified to formulate vegetable based cutting fluid (VBCF) of castor oil for the formation of emulsion as non –conventional lubricant. The mineral oil based cutting fluid emulsion is also used for turning operation as conventional lubricant. Experimentation has been carried out for different combinations. Cutting fluid, cutting velocity, feed rate and depth of cut are considered as machining parameters. Then machining with conventional and non-conventional lubricants in wet condition has been carried out upon SS 316 L work piece with carbide cutting inserts tool, to evaluate cutting forces and tool wear. The results show that non-conventional lubricant performs better than conventional cuttingfluid.

CUTTING FLUID OILY WASTEWATER: BREAKDOWN AND REUSE OF THE RECOVERED OIL PHASE

The aim of this work is to evaluate the use of electrolytes in the breakdown of waste by cutting fluid emulsions, reusing the recovered oil phase to develop new cutting fluids. Four cutting fluids were used to obtain oily emulsions: two commercial, OP38 (Lubrax) and Dromus (Shell), and two developed formulations, CF1 and CF2. The emulsions were prepared by using 5 to 30 wt.% cutting fluid in water. NaCl and CaCl2 solutions were used to promote the destabilization of emulsions, taking into account the percentage of oil recovered as a function of time, observing the influence of type and concentration of electrolyte, temperature, and emulsion droplet size. The aqueous effluent obtained after oil phase removal was characterized by turbidity, oil and grease content, pH, and presence of anions and cations. The use of CaCl2 (2 wt.%), at 25°C, provided the best results in emulsion breakdown and the best quality of the water phase. All the parameters evaluated in these water phases were in accordance with the specifications established by Brazilian legislation that regulates the disposal of wastewater in surface waters. The physicochemical properties of the recovered oil phases were compared with the ones of the mineral oil NH-20 used to obtain CF1 and CF2. It was verified an increase in total acid number, viscosity and corrosiveness to copper. Additives were added to the recovered oil phases to obtain new cutting fluids. The physicochemical properties of these new cutting fluids were close to the ones of the initial ones, except for the viscosity values which increased.

Cutting fluid emulsions produced by dilution of a cutting fluid concentrate containing a cationic/nonionic surfactant mixture

A cutting fluid concentrate has been formulated from a paraffinic oil, a hard water, MonoEthanolamine Borate (MEAB) and a cationic/nonionic surfactant mixture. Its dilution with hard water yields very stable oil-in-water emulsions, the so-called cutting fluid emulsion, with an average droplet diameter of 50 nm, independently of both the hardness of water and the weight ratio of hard water to concentrate. The high stability of these emulsions results from the existence of a strong repulsive potential between droplets which is caused in particular by the presence of the cationic surfactant at their surface. From a practical point of view, the ability to produce stable cutting fluid emulsions for a wide range of dilution, whatever the hardness of water, might allow the user to fine-tune the lubricating and cooling abilities of the fluids and therefore optimize their performances during the metal working process.

Tool wear and failure in the drilling of stainless steel

Three studies on the tool behaviour in the cutting of stainless steel, which is a work-piece material with a relatively poor machinability, are presented. In the first study, three cutting fluids are evaluated, in the second two different high-speed steel (HSS) tool materials are compared; one of them as uncoated and as TiN-coated. Finally, the suitability of some on-line measurements for tool-monitoring methods are studied. The differences in the behaviour of three cutting fluid emulsions observed in the drilling of stainless steel with the tools of high speed steel were significant enough to facilitate ranking of the fluids. The test method presented may be adapted as a method for cutting fluid testing in industry. The main result of the tests with different drill materials was that more expensive bright drills with or without TiN-coating had a lower productivity than the less expensive black drills. This is due to the low feed rate values causing a strong decrease in the chip flow rate. The on-line measurement results show that all the quantities measured remain at an almost constant level during the entire tool life-time until the hole in which the drill totally fails. Therefore it is impossible to successfully apply these measurements as tool monitoring methods, stopping the machining after the increase in one or several signals above a certain limit value before an actual tool failure. However, the measurements can be used for tool breakage detection where the machining operation is interrupted after a tool breakage.

Simple Circulating Tank Test for Evaluation of Germicides in Cutting Fluid Emulsions

Simple Circulating Tank Test for Evaluation of Germicides in Cutting Fluid Emulsions

Simple Circulating Tank Test for Evaluation of Germicides in Cutting Fluid Emulsions

Simple Circulating Tank Test for Evaluation of Germicides in Cutting Fluid Emulsions

Antimicrobial Performance of Tri- and Tetrachloro-4-(Methylsulfonyl) Pyridines as Industrial Preservatives

Tests show that trichloro- and tetrachloro-4-(methylsulfonyl) pyridines have a wide spectrum of activity against microorganisms causing deterioration in industrial systems. They are particularly active as fungistats and are more effective against gram-positive than against gram-negative bacteria. Their fungistatic activity and persistence have led to outstanding performance as mildewcides in exterior paints. In addition, we report the performance of these compounds as preservatives in the following products: asphalt, calking compositions, joint cements, paper, plastics, soluble oils (cutting fluid emulsions), and textiles.

Antimicrobial Performance of Tri- and Tetrachloro-4-(Methylsulfonyl) Pyridines as Industrial Preservatives

Tests show that trichloro- and tetrachloro-4-(methylsulfonyl) pyridines have a wide spectrum of activity against microorganisms causing deterioration in industrial systems. They are particularly active as fungistats and are more effective against gram-positive than against gram-negative bacteria. Their fungistatic activity and persistence have led to outstanding performance as mildewcides in exterior paints. In addition, we report the performance of these compounds as preservatives in the following products: asphalt, calking compositions, joint cements, paper, plastics, soluble oils (cutting fluid emulsions), and textiles.