Removal Machining Performances by Using Inert Gas Filled Micro Bubble Coolant

Author(s):  
Manabu Iwai ◽  
Ryouta Yamashita ◽  
Satoshi Anzai ◽  
Shinichi Ninomiya

Abstract The authors have proposed a micro bubble coolant in which micro bubbles (20∼50μm in diameter) are included in water soluble coolant. In the previous study, it was confirmed that the tool life was improved by applying the micro bubble coolant to various machining operations such as drilling, turning and grinding. Also, purification effects of the micro bubble coolant were found. In this study, micro bubble coolant in which inert gases (N2 and CO2) were mixed was proposed to be applied to grinding processes for further improvement in grinding performances. When nitrogen gas (2L/min) was mixed with the micro bubble in the water soluble coolant (70L), amount of the dissolved oxygen in coolant decreased to 0.5mg/L. And concentration of the carbon dioxide gas in the coolant increased to 100mg/L when carbon dioxide gas (2L/min) was mixed in. From the result of grinding test on high speed steel, it was found that grinding performances improved when the micro bubble coolant with any of air, N2 and CO2 gases was used. The grinding force decreased by a factor of about 15% and the tool life increased by 20∼30%. When nitrogen gas was mixed in, the surface roughness improved by about 15%. In grinding stainless steels, performances such as grinding force, tool life and surface roughness improved by 10% when nitrogen gas was mixed in. In addition, a tendency of flank wear reduction and improvement in the surface roughness were observed when air micro bubble was mixed into the coolant in the turning of high carbon steel and Inconel 718 as well. When N2 micro bubble was generated in the coolant, a flank wear was reduced by 20% and surface roughness was improved by 30 to 40%. These effects were higher than the coolant with air micro bubble.

2014 ◽  
Vol 800-801 ◽  
pp. 191-196
Author(s):  
Bin Zhao ◽  
Han Lian Liu ◽  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Hong Tao Zhu

The nickel-based superalloy GH4033 is one of the difficult-to-cut materials. In order to investigate the machinability of GH4033, the tool cutting performance, tool failure modes, tool life and the relationships between surface roughness and tool flank wear were studied by using different coated cemented carbide cutting tools under dry cutting. Aiming at the amount of metal removal combining with the tool life and surface quality, the better cutting tool coating type and optimal cutting parameters were obtained through the orthogonal experiments. The results showed that the cutting performance of TiCN coated tool (GC4235) was better than that of TiAlN coated tool (JC450V). With these two kinds of tools, the machined surface roughness decreased to a minimum value and then increased with the increase of flank wear. When cutting GH4033, the main wear mechanism for both of the two types of tools included adhesive wear, diffusive wear, abrasive wear, edge wear and coating peeling.


2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Yunn-Shiuan Liao ◽  
Tsung-Hsien Li ◽  
Yi-Chen Liu

Abstract Application of liquid carbon dioxide to improve cutting performance in micro-end milling of Ti-6Al-4V titanium alloy was proposed in this study. It was found that the machined roughness decreased with the cutting speed as observed in the conventional cutting, when a 0.5 mm diameter end milling cutter was used in dry cutting. But, the tiny and shattered chips produced by the use of 0.3 mm diameter cutter could adhere on the machined surface and deteriorate surface finish, if the cutting speed was higher than 40 m/min. Cutting temperature was effectively decreased by applying liquid carbon dioxide during micromilling, which in turn reduced the amount of chips adhering on the machined surface and lowered flank wear. The surface roughness Ra at a cutting speed of 70 m/min was improved from 0.09 μm under dry cutting to 0.04 μm under the liquid carbon dioxide assisted cutting condition. And there were no flank wear and very few burrs left on the machined surface for the condition used in the experiment. The height of the burrs was only 25% of that under dry cutting. More, minimum quantity lubrication (MQL) was proposed to be applied together with the liquid carbon dioxide to enhance lubrication effect. It was noted that the machined surface roughness was further decreased by 15% as compared with that when the liquid carbon dioxide was applied alone. The height of burrs was reduced from 32 μm to 16 μm.


2020 ◽  
Vol 22 (4) ◽  
pp. 41-53
Author(s):  
Manojkumar Sheladiya ◽  
◽  
Shailee Acharya ◽  
Ghanshyam Acharya ◽  
◽  
...  

Introduction. The machinability is typical criteria to be investigated and different authors suggested different parameters describing its quantification. Different parameters i. e. speed, feed, depth of cut, tool work-piece combination, machine types and its condition, cutting fluid, machinist expertise, etc. are contributing directly to the tool life. The selection of the tool for the machining impacts greatly on the economic viability of the machining in terms of energy usage and tooling costs. The method of investigation. The current research emphasis mainly on tool life investigation when machining the mild steel specimens ISRO 50, BIS 1732:1989 at constant cutting speed i.e. 200 m / min. In the industries the mild steel material is commonly used for various products manufacturing. Considering the high demands on productivity and surface finish, machining at 200 m / min is the preferred. The computerized numerical control machine (CNC DX-150) is used for the turning. The four corner insert (TNMG 120408) is used for different machining times i.e. 10, 15, 20 and 25 minutes respectively. The flank wear of the tool is measured with calibrated optical microscope. The temperature of the tool corner during machining is continuously measured for possible impact of temperature on bonding properties of the tool insert and impact on red hardness. Results and discussion. The plot of flank wear vs. machining time will give the value of tool life. The other quality output parameter, such as surface roughness, is measured after machining, indicating surface irregularities in root means square value. Efforts have been made to identify the relationship of tool life, machining time, the quantity of metal removed, surface roughness, and tool bit temperature.


2019 ◽  
Vol 18 (04) ◽  
pp. 625-655 ◽  
Author(s):  
Asutosh Panda ◽  
Sudhansu Ranjan Das ◽  
Debabrata Dhupal

The present study addresses the machinability investigation in finish dry hard turning of high strength low alloy steel with coated ceramic tool by considering cutting speed, feed and depth of cut as machining parameters. The technological parameters like surface roughness, flank wear, chip morphology and economical feasibility have been considered to investigate the machinability performances. Twenty seven set of trials according to full factorial design of experiments are performed and analysis of variance, multiple regression method, Taguchi method, desirability function approach and finally Gilbert’s approach are subsequently applied for parametric influence study, mathematical modeling, multi-response optimization, tool life estimation and economic analysis. Results indicated that feed and cutting speed are the most significant controlled as well as dominant factors for hard turning operation if the minimization of the machined surface roughness and tool flank wear is considered. Abrasions, adhesion followed by plastic deformation have been observed to be the principal wear mechanism for tool life estimation and observed tool life for coated ceramic insert is 47[Formula: see text]min under optimum cutting conditions. The total machining cost per part is ensued to be lower ($0.29 only) as a consequence of higher tool life, reduction in downtime and enhancement in savings, which finds economical benefits in hard turning. The current work demonstrates the substitution of conventional, expensive and slow cylindrical grinding process, and proposes the most expensive CBN tool alternative using coated ceramic tools in hard turning process considering techno-economical and ecological aspects.


2012 ◽  
Vol 538-541 ◽  
pp. 1245-1249 ◽  
Author(s):  
Ze Wu ◽  
Jian Xin Deng ◽  
Jun Zhao

Surface textured tools were fabricated by laser beam machining. Dry cutting of Ti-6Al-4V alloys was carried out with these surface textured tools and conventional tools for comparison. The cutting temperature, tool flank wear and surface roughness of processed workpiece were measured. The experimental formulas of tool life based on DOT method were developed. Results show that the surface textured tool can reduce the surface roughness of workpiece, and the tool life of surface textured tool is improved by 15% or so compared with the conventional one.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1311
Author(s):  
Farhana Yasmin ◽  
Khairul Fikri Tamrin ◽  
Nadeem Ahmed Sheikh ◽  
Pierre Barroy ◽  
Abdullah Yassin ◽  
...  

Laser-assisted high speed milling is a subtractive machining method that employs a laser to thermally soften a difficult-to-cut material’s surface in order to enhance machinability at a high material removal rate with improved surface finish and tool life. However, this machining with high speed leads to high friction between workpiece and tool, and can result in high temperatures, impairing the surface quality. Use of conventional cutting fluid may not effectively control the heat generation. Besides, vegetable-based cutting fluids are invariably a major source of food insecurity of edible oils which is traditionally used as a staple food in many countries. Thus, the primary objective of this study is to experimentally investigate the effects of water-soluble sago starch-based cutting fluid on surface roughness and tool’s flank wear using response surface methodology (RSM) while machining of 316 stainless steel. In order to observe the comparison, the experiments with same machining parameters are conducted with conventional cutting fluid. The prepared water-soluble sago starch based cutting fluid showed excellent cooling and lubricating performance. Therefore, in comparison to the machining using conventional cutting fluid, a decrease of 48.23% in surface roughness and 38.41% in flank wear were noted using presented approach. Furthermore, using the extreme learning machine (ELM), the obtained data is modeled to predict surface roughness and flank wear and showed good agreement between observations and predictions.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1628
Author(s):  
Mohd Fathullah Ghazali ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Shayfull Zamree Abd Rahim ◽  
Joanna Gondro ◽  
Paweł Pietrusiewicz ◽  
...  

This paper reports on the potential use of geopolymer in the drilling process, with respect to tool wear and surface roughness. The objectives of this research are to analyze the tool life of three different economy-grade drill bit uncoated; high-speed steel (HSS), HSS coated with TiN (HSS-TiN), and HSS-cobalt (HSS-Co) in the drilling of geopolymer and to investigate the effect of spindle speed towards the tool life and surface roughness. It was found that, based on the range of parameters set in this experiment, the spindle speed is directly proportional to the tool wear and inversely proportional to surface roughness. It was also observed that HSS-Co produced the lowest value of surface roughness compared to HSS-TiN and uncoated HSS and therefore is the most favorable tool to be used for drilling the material. For HSS, HSS coated with TiN, and HSS-Co, only the drilling with the spindle speed of 100 rpm was able to drill 15 holes without surpassing the maximum tool wear of 0.10 mm. HSS-Co exhibits the greatest tool life by showing the lowest value of flank wear and produce a better surface finish to the sample by a low value of surface roughness value (Ra). This finding explains that geopolymer is possible to be drilled, and therefore, ranges of cutting tools and parameters suggested can be a guideline for researchers and manufacturers to drill geopolymer for further applications.


2009 ◽  
Vol 76-78 ◽  
pp. 651-656 ◽  
Author(s):  
Shinichi Ninomiya ◽  
Manabu Iwai ◽  
Toshiharu Shimizu ◽  
Tetsutaro Uematsu ◽  
Kiyoshi Suzuki
Keyword(s):  

The authors have proposed a new coolant named “micro bubble coolant” in which micro bubbles (20-50µm in diameter) are included. In the previous study, it was clarified that the tool life is improved by applying this new coolant to various machining such as boring, turning and grinding. This paper deals with purification effect of the micro bubble coolant. It has been found from the experiments that bacteria which cause putrefaction of the conventional water soluble coolant are eliminated by generating micro bubbles in the coolant. It has also been clarified that the micro bubble coolant isolates minute machined chips and machine oil from the coolant.


1997 ◽  
Vol 119 (4A) ◽  
pp. 580-586 ◽  
Author(s):  
A. R. Machado ◽  
M. F. Motta ◽  
M. B. da Silva

The present work shows a comparative study of the application of synthetic and semi synthetic, mineral soluble oil (at concentrations of 3 and 10 percent) as well as dry cut when turning AISI 8640 steel bars with triple coated (TiC,Al2O3,TiN) P35 grade of cemented carbide tools. Tool lives, cutting forces, cutting temperatures and surface roughness were considered to evaluate the cutting fluids. Generally, the semi-synthetic gave longer tool life based on flank wear parameter VB. The surface roughness was not sensitive to the lubrication quality, if wear effects are not considered. Mean tool-chip interface temperature was lower with the synthetic fluid, followed by the semi-synthetic, mineral soluble oils and dry cutting, respectively. The inverse of this order was true for the cutting forces.


Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 168 ◽  
Author(s):  
Jianbing Meng ◽  
Bingqi Huang ◽  
Xiaojuan Dong ◽  
Yizhong Hu ◽  
Yugang Zhao ◽  
...  

There are high cutting temperatures, large tool wear, and poor tool life in conventional machining, owing to the superior strength and low thermal conductivity of titanium alloy. In this work, ultrasonic atomization assisted turning (UAAT) of Ti6Al4V was performed with a mixed water-soluble oil-based cutting fluid, dispersed into tiny droplets by the high frequency vibration of a piezoelectric crystal. Different cutting speeds and two machining environments, dry and ultrasonic atomization assisted machining, were considered in the investigation of tool life, tool wear morphology, surface roughness, and chip morphology. In comparison with dry machining, UAAT shows lower tool wear and longer tool life due to the advantages of cooling and lubrication. Furthermore, better surface roughness, smoother chip edges, and shorter tool-chip contact length were obtained with UAAT.


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