Biological Stability of Water-Based Cutting Fluids:Progress and Application

The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based cutting fluid accounts for more than 90%of the consumption of cutting fluid.However,long-term recycling of water-based cutting fluid could easily cause deterioration,and the breeding of bacteria could cause the cutting fluid to fail,increase manufacturing costs,and even endanger the health of workers.Traditional bactericides could improve the biological stability of cutting fluids,but they are toxic to the environment and do not conform to the development trend of low-carbon manufacturing.Low-carbon manufacturing is inevitable and the direction of sustainable manufacturing.The use of nanomaterials,transition metal complexes,and physical sterilization methods on the bacterial cell membrane and genetic material could effectively solve this problem.In this article,the mechanism of action of additives and microbial metabolites was first analyzed.Then,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were summarized.Further,the mechanism of nanomaterials disrupting cell membrane potential was discussed.The effects of lipophilicity and the atomic number of transition metal complexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were reviewed.In other words,the bactericidal performance,hazard,degradability,and economics of various sterilization methods were comprehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.

Determining the Effect of Cutting Fluids on Surface Roughness in Turning AISI 1330 Alloy Steel Using Taguchi Method

Taguchi method has been employed to investigate the effects of cutting fluids on surface roughness in turning AISI 1330 alloy steel, using manually operated lathe machine. Experiments have been conducted using L27 (34) orthogonal array and each experiment was repeated three times and each test used a new cutting tool, High Speed Steel (HSS), to ensure accurate readings of the surface roughness. The statistical methods of Signal-to-Noise (S/N) ratio and the Analysis of Variance (ANOVA) were applied to investigate effects of cutting speed, feed rate and depth of cut on surface roughness under different cutting fluids. Minitab 14 software was used to analyze the effect of variables on the surface roughness. Results obtained indicated that optimal variables for the minimum surface roughness were cutting speed of 35 m/min (level 2), feed of 0.124 mm/rev (level 1), depth of cut of 0.3 mm (level 1) and a cutting fluid with a viscosity of 2.898 mm2/s (level 3). Hence, the optimal parameters to obtain better surface roughness of the workpiece material were obtained when groundnut oil based cutting fluid was used. Analysis of variance shows that feed rate has the most significant effect on surface roughness.

Investigation of Nanofluids as Potential Cutting Fluids in Gear Hobbing Processes of AISI 4118 Steel

The present work focuses on the performance of nanofluids called CN46-NanoAl2O3.80 formulated by using dispersions of nano aluminum oxide （Al2O3） in the ISO VG46 industrial oil on machining performance during gear hobbing of AISI 4118 steel. In machining gears, hobbing is one of the most important processes, especially to produce various gear shapes for adapting to diverse applications. However, the demand for high quality brings attention to product quality, particularly the roughness of the machined gear surface because of its effect on product appearance, function, and reliability. For additional improvement, applying nanofluids may produce superior product quality, as the rolling action of billions of nanoparticle units in the tool chip interface can significantly decrease the friction led to reduce the cutting forces. In addition, the characteristics of heat transfer of nanoparticles can contribute to reduce tool wear. In this experimental study, the performance of nanolubricant compared with the case of using ordinary cutting-fluid systems in the existing production line is investigated. The experimental results reveal that the tool life of the hob is significantly enhanced of 55.2%, gear surface roughness is smaller （27.3%）, and gear accuracy is significantly increased by using the nanofluid. This result, therefore, shows a promising solution to achieve the engineering-economy effectiveness in gear machining.

Vegetable and Mineral Used Oils as Cutting Fluids: Effect on Surface Roughness of Aluminum Alloy

The use of cutting fluids in mechanical machining operation is important to make cutting easy, produce low surface roughness, increase the rate of productivity, and alleviate the negative effect on work environment and operators. In this project the effect of using different cutting fluids on the surface roughness of aluminum alloy (T6-6061) was studied. The experiment involved the use of constant cutting parameters (cutting speed of 860 rpm, depth of cut at 1.5 mm, and feed rate of 0.12 mm/rev). Three local cutting fluids: mineral used oil, kerosene, and natural used oil (refined sunflower oil) mixed with water at different ratios (5%, 10%, 15%, 20%, and 25%) were used to study their effect on the surface roughness compared to a common lubricate oil used in the cooling process. Results revealed that mineral used oil gave the lowest (best) roughness coefficient at 5% water ratio followed by lubricate oil. Kerosene and natural oil had the highest roughness coefficients. Mineral oil could be recommended for use with local cutting machines reducing the huge amounts of waste oil produced in the country.

Assessment of water-based cutting fluids with green additives in broaching

In order to improve the cutting performance in broaching,the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing.Therefore,water-based solutions with castor oil,surfactant(linear alkylbenzene sulfonate,LAS),and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via atomization.The performances of the cutting fluids,in terms of the viscosity,specific heat,wetting angle,and droplet size,were evaluated to discuss their effects on the broaching load.Among the fluids,the addition of LAS into oil-in-water(WO-S),where its cutting fluid with 10 wt.%castor oil and 1.5 wt.%surfactant,exhibited the lowest broaching force.With regard to the lubricating and cleaning mechanisms,WO-S has good wettability and permeability,and hence,can lubricate the cutting edge of the tool to decrease the cutting load,cool the cutting edge to keep it sturdy,and clean the surface of the cutting edge to keep it sharp.The results reveal that the simultaneous addition of castor oil and LAS had remarkable effects on the lubrication and cleaning,and resulted in a broaching load reduction of more than 10%compared to commercial cutting fluids.However,the addition of nanographite could not improve the lubrication owing to its agglomeration.

A Decision-Making Framework Model of Cutting Fluid Selection for Green Manufacturing and the Case Study

Pursuing the green manufacturing (GM) of products i s very beneficial in the alleviation of environment burdens. In order to reap such benefits, green manufacturing is involved in every aspect of manufacturing proc esses. During the machining process, cutting fluid is one of the main roots of e nvironmental pollution. And how to make an optimal selection for cutting fluid f or GM is an important path to reduce the environmental pollution. The objective factors of decision-making problems in the traditional selection of cutting flu id are usually two: quality and cost. But from the viewpoint of GM, environmenta l impact (E) should be considered together. In this paper, a multi-object d ecision-making model of cutting fluid selection for GM is put forward, in which the objects of Quality (Q), Cost(C) and Environmental impact (E) are considered together. In this model, E means to minimize the environmental impact, Q means to maximize the quality and C means to minimize the cost. Each objective is anal yzed in detail too. A case study on a decision-making problem of cutting fluid selection in a gear hobbing process is analyzed, and the result shows the model is practical.

Scratching and Turning Experiments on Machinability of Optical Glass SF6 in Diamond Cutting Process

To improve the machinability of optical glass and achieve optical parts with satisfied surface quality and dimensional accuracy, scratching experiments with increasing cutting depth were conducted on glass SF6 to evaluate the influence of cutting fluid properties on the machinability of glass. The sodium carbonate solution of 10.5% concentration was chosen as cutting fluid. Then the critical depths in scratching experiments with and without cutting fluid were examined. Based on this, turning experiments were carried out, and the surface quality of SF6 was assessed. Compared with the process of dry cutting, the main indexes of surface roughness decrease by over 70% totally. Experimental results indicated that the machinability of glass SF6 can be improved by using the sodium carbonate solution as cutting fluid.

Nano K_2Ti_4O_9 Whisker Enhanced Solid Lubrication Coating for Cutting Application

In order to decrease cutting fluid and improve environment, the cutting fluid was replaced by solid lubricant. Four kinds of solid lubricants were tested on a high temperature friction tester, from which nano K 2Ti 4O 9 whisker enhanced solid lubrication film was chosen. It was coated on the surface of cutters and tested on a CA6140 lathe. At the rate of 400r/min, the wear of the tool flank with solid lubrication film is 1/6 of that without the film, and it is even lower than that using cutting fluid. With the increase of cutting speed, the wear of the tool flank with solid lubrication film is still lower than that without film, but it is higher than that using cutting fluid. Surface analyses by AFM, SEM and EDX reveal that the solid lubrication film can prevent Fe element of chips from diffusing the cutter surface; adhesion of the cutter and chips is abated and the wear of the tool flank is obviously decreased.

Vegetable Oil-Based Nanolubricants in Machining:From Physicochemical Properties to Application

Cutting fluid is crucial in ensuring surface quality and machining accuracy during machining.However,traditional mineral oil-based cutting fluids no longer meet modern machining’s health and environmental protection require-ments.As a renewable,pollution-free alternative with excellent processing characteristics,vegetable oil has become an inevitable replacement.However,vegetable oil lacks oxidation stability,extreme pressure,and antiwear proper-ties,which are essential for machining requirements.The physicochemical characteristics of vegetable oils and the improved methods’application mechanism are not fully understood.This study aims to investigate the effects of viscosity,surface tension,and molecular structure of vegetable oil on cooling and lubricating properties.The mechanisms of autoxidation and high-temperature oxidation based on the molecular structure of vegetable oil are also discussed.The study further investigates the application mechanism and performance of chemical modification and antioxidant additives.The study shows that the propionic ester of methyl hydroxy-oleate obtained by epoxidation has an initial oxidation temperature of 175℃.The application mechanism and extreme pressure performance of conventional extreme pressure additives and nanoparticle additives were also investigated to solve the problem of insufficient oxidation resistance and extreme pressure performance of nanobiological lubricants.Finally,the study discusses the future prospects of vegetable oil for chemical modification and nanoparticle addition.The study provides theoretical guidance and technical support for the industrial application and scientific research of vegetable oil in the field of lubrication and cooling.It is expected to promote sustainable development in the manufacturing industry.

MQL:A New Way to Clean Production

Cost, the effect on the environment, and health issues are relevant when considering the choice of a lubricant and application system in a modern metal cutting process. This paper provided a general introduction to metalworking fluids, reviewed the benefits and negative effects attributed to the production of mist during cutting processes. Due to the increasing concern over workers exposed to cutting fluid mist, and to achieve the recommended exposure limit, much attention was focused on how to minimize or prevent the mist formation. Different proposed techniques were analyzed, each of them has its advantages and limitations. Finally, the benefits of minimum quantity of lubrication (MQL) technique over all other techniques were studied.

Modeling the effects of mechanical parameters on the hydrodynamic behavior of vertical current classifiers

This study modeled the effects of structural and dimensional manipulations on hydrodynamic behavior of a bench vertical current classifier. Computational fluid dynamics （CFD） approach was used as modeling method, and turbulent intensity and fluid velocity were applied as system responses to predict the over- flow cut size variations. These investigations showed that cut size would decrease by increasing diameter and height of the separation column and cone section depth, due to the decrease of turbulent intensity and fluid velocity. As the size of discharge gate increases, the overflow cut-size would decrease due to freely fluid stream out of the column. The overflow cut-size was significantly increased in downward fed classifier compared to that fed by upward fluid stream. In addition, reforming the shape of angular overflow outlet＇s weir into the curved form prevented stream inside returning and consequently unselec- tire cut-size decreasing.

MODELING AND OPTIMIZATION OF THE CUTTING FLUID FLOW AND PARAMETERS FOR INCREASING TOOL LIFE IN SLOT MILLING ON St52

In this paper the CNC machining of St52 was modeled using an artificial neural network(ANN)in the form of a four-layer multi-layer perceptron(MLP).The cutting parameters used in the model were cutting fluid flow,feed rate,spindle speed and the depth of cut and the model output was the tool life.For obtaining more accuracy and spending less time Taguchi design of experiment(DOE)has been used and correlation between the output of the ANN and the experimental results was 96%.Further optimization process has been done by use of a genetic algorithm(GA).After optimization process tool life was increased about 8%equal to 33 min and was corroborated by experimental tests.This demonstrates that the coupling of an ANN with the GA optimization technique is a valid and useful approach to use.

Penetration and lubrication evaluation of vegetable oil with nanographite particles for broaching process

With increasing environmental concerns,the substitution of mineral oil-based cutting fluid has become an urgent issue.Using vegetable soybean oil as base fluid,nanofluid cutting fluids(NFCFs)were prepared by adding different weight concentrations of nanographite particles(NGPs),and their penetration and lubrication performances were studied.A novel simulated tool-chip slit with micrometersized geometry was manufactured to evaluate and quantify the penetration rate of the NFCFs by image analysis approach.Moreover,a large number of comparative experiments on the closed-type broaching machine were carried out to compare the performance of the proposed NFCFs and a commercial cutting fluid in terms of cutting force,workpiece surface roughness,and metal chip.It is found that there is an optimal NGP concentration in NFCF for practical cutting applications.When the concentration of NGP is 0.4 wt%,the broaching process lubrication exhibits an ideal mixed lubricate state,resulting in minimal friction resistance,and thus,both the cutting force and chip curling angle reach their corresponding best values.Moreover,the proposed NGP-based vegetable-oil cutting fluid exhibits excellent environmentfriendliness and low-cost consumption in the minimal quantity lubrication(MQL)method;this demonstrates its potential for replacing the traditional broaching cutting fluid.