Development of an Imaging System and Its Application in the Study of Cutting Fluid Atomization in a Turning Process

Different parameters (air pressure, quantity of minimum quantity lubrication (MQL) oil, position of nozzle, etc.) of an MQL system have different effects on the milling force and milling temperature. The cutting force and cutting temperature, which are closely related to lubrication and coolant, play significant roles in improving/reducing the cutting quality of a workpiece and extending/shortening the tool life. The present work investigates experimentally the effects of different MQL parameters (air pressure, quantity of oil consumed, and position of the nozzle) in end-milling titanium alloy (Ti–6Al–4V). The experimental results show that the penetrating ability of MQL oil mist has a significant effect on the milling forces and milling temperatures. When the values of air pressure and spraying distance were either too large or too small, it is not good for oil mist to penetrate into the contact zones. The spraying angle of the nozzle position has a minimal impact on the penetration ability. Conversely, the amount of oil delivery is the most important part of MQL application. The minimum quantity of oil consumption can be obtained. The results will help to select optimum MQL parameters in end-milling titanium alloy.

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“…The droplet diameter (d) of the oil mist is determined by the fluid flow speed () or air pressure (p). Two equations were given by Ju [9]…”

Section: Effects Of Air Pressurementioning

confidence: 99%

Investigation of cutting force and temperature of end-milling Ti–6Al–4V with different minimum quantity lubrication (MQL) parameters

Liu

Cai

Chen

et al. 2011

Proceedings of the Institution of Mechanical Engineers, Part B:

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“…For an imaging system with parameters shown in Figure 1, the image intensity of an opaque circular disk was obtained by Bongiovanni et al [13]. In this figure, R is the radius of the circular disk, r x 2 0 y 2 0 p is the distance from the optical axis, r ent is the radius of the entrance pupil, and L ent represents the distance from the entrance pupil to the object plane of focus.…”

Section: Image Formation Model Based On Geometrical Opticsmentioning

confidence: 99%

A Numerical Calibration Approach to Obtain Cutting Fluid Droplet Sizes in a Turning Process via an Imaging System

Michalek

Sutherland

2012

Part & Part Syst Charact

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Airborne inhalable particulate in the workplace can represent a significant health hazard, and one of the primary sources of particles is mist produced through the application of cutting fluids in machining operations. The atomization process is one of the principal mechanisms associated with cutting fluid mist formation and generates droplets from fifty to a few thousand micrometers in size. These particles subsequently undergo vaporization and settling effects resulting in an aerosol to which workers may be exposed. While a variety of equipment is available to characterize the fine particulate in the breathing zone, standard equipment to measure the size of the atomized droplets is not available. In this paper, an imaging system is employed to characterize the large droplets produced by atomization in turning. One of the drawbacks of such a system is the time‐consuming experimental calibration procedure that is required to improve the accuracy of the droplet size measurements and extend the depth of field of the imaging system. With this in mind, an approach is introduced to predict droplet diameter based on measurement data without physical system calibration. The relationship between the actual diameter and the measured diameter is established based on an imaging system simulation model that includes a three dimensional point spread function and an image formation relationship grounded in the principles of geometric optics. These two components are combined using convolution integral theory to derive an image intensity profile. The introduction of halo width into the simulation greatly extends the image depth of field, which is a critical factor in capturing more droplets in one image and also minimizing particle size distribution bias towards larger droplets. The model predicts droplet diameter as a function of measured diameter and halo width. Model behavior of predicted diameters from the simulation compares well with those from a physical calibration of the system. The numerical calibration model is then used in the study of cutting fluid atomization in a turning process, and the measured droplet size distribution compares favorably with droplet sizes predicted by a mechanistic atomization model.

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“…This model can calculate the liquid film flow rate, the number of liquid ligaments and the SMD of the oil particles. Ju et al 28 developed a measurement system for size distribution of oil particles using charge-coupled device (CCD) photography and image processing technology. Michalek et al 29 established a mathematical model for calculating the maximum atomization flow rate and the average particle size on the basis of film theory.…”

Section: Introductionmentioning

confidence: 99%

A prediction model of emission characteristics of oil particles induced by milling process: Emission rate and size distribution

Wang

et al. 2022

Indoor and Built Environment

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The use of metalworking fluids (MWFs) in the milling process can cause emissions of a large amount of oil particles, which can induce respiratory and immune system diseases of workers. This work examined the emission characteristics of oil particles caused by the milling process. A closed test chamber containing a real milling machine was built. The emission rates of oil particles in various sizes using five kinds of MWFs were measured, and the influence of the rotation speed of the spindle in the milling machine and the physical properties of MWFs on the oil particle emission characteristics was analysed. In addition, a prediction model of emission rate and size distribution of oil particles was introduced. Based on the measured data of oil particle emission rates in each size, the morphological particle size, distribution index and atomization coefficient in the prediction model are fitted. The deviation between the predicted and measured values of the emission rates is about 5%, which confirms the accuracy of the model. The prediction model is helpful for pollution control and ventilation strategy formulation in typical machining plants.

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Development of an Imaging System and Its Application in the Study of Cutting Fluid Atomization in a Turning Process

Cited by 5 publications

References 17 publications

Investigation of cutting force and temperature of end-milling Ti–6Al–4V with different minimum quantity lubrication (MQL) parameters

Investigation of cutting force and temperature of end-milling Ti–6Al–4V with different minimum quantity lubrication (MQL) parameters

A Numerical Calibration Approach to Obtain Cutting Fluid Droplet Sizes in a Turning Process via an Imaging System

A prediction model of emission characteristics of oil particles induced by milling process: Emission rate and size distribution

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