The process of cryogenic machining, due to increased demand for environmentally friendly manufacturing processes, has seen a growing interest in the machining community. This article presents an overview of cryogenic machining and its... more
The process of cryogenic machining, due to increased demand for environmentally friendly manufacturing processes, has seen a growing interest in the machining community. This article presents an overview of cryogenic machining and its induced surface integrity characteristics such as surface roughness, topography, grain refinement and machining-induced layer, microhardness, phase transformation, residual stress and fatigue life in machining of various materials including difficult-to-machine materials, aerospace alloys, lightweight materials, etc. The effect of cryogenic machining on surface integrity characteristics is discussed, and compared with dry, Minimum Quantity Lubrication (MQL), and flood-cooled machining processes. In addition to being an environmentally friendly process, this study shows that cryogenic machining significantly contributes to improved functional performance of machined components through its superior and more desirable surface integrity characteristics.
During metal cutting operation, cutting fluid plays a vital role by cooling and lubricating the tool-work piece interface and removing chips from the cutting zone. As a result, a cutting fluid may significantly affect the tribological... more
During metal cutting operation, cutting fluid plays a vital role by cooling and lubricating the tool-work piece interface and removing chips from the cutting zone. As a result, a cutting fluid may significantly affect the tribological conditions at these interfaces. However, human health and environment both are affected negatively by the excessive use of conventional cutting fluid. This has led to the development of a new class of cutting fluid with superior thermal and tribological properties to restrict its extravagant use during machining. A colloidal mixture of metallic or non-metallic nano meter sized particles in a base fluid is called nanofluid. For the last one decade, nanofluids have attracted the attention of researchers due to its improved thermal conductivity and heat extraction capability. In the present work, a new nanofluid is prepared by mixing Al 2 O 3 nanoparticles in conventional cutting fluid at different concentrations. The prepared nanofluid is characterized for its thermal conductivity and viscosity at all nanoparticle concentrations. Furthermore, its machining performance is examined in turning workpiece of AISI 1040 steel using minimum quantity lubrication (MQL) technique. The results are also compared with that of dry machining and wet/MQL machining using conventional cutting fluid. The experimental study clearly reveals that performance of Al 2 O 3 nanofluid in terms of surface roughness, tool wear, cutting force and chip morphology is found to be better compared to dry machining, wet machining with conventional cutting fluid and MQL using conventional cutting fluid.
Applying cutting fluid in a metal-cutting process can reduce the rate of tool wear and improve surface quality. However, cutting fluid has negative effects on the working environment and the use of cutting fluid also increases the total... more
Applying cutting fluid in a metal-cutting process can reduce the rate of tool wear and improve surface quality. However, cutting fluid has negative effects on the working environment and the use of cutting fluid also increases the total production cost. Therefore, there is a need to reduce the use of cutting fluid during machining. To serve that purpose, a minimal-cutting-fluid technique was studied. In the present work the cutting fluid was applied in a form of a high-velocity, narrow, pulsed jet at a rate of 2 ml/min. The performance of machining with pulsed-jet application was studied in high-speed milling of hardened steel, compared to dry machining and machining with flood application. The results clearly show that compared to dry machining and machining with flood application, machining with pulsed-jet application lowers cutting forces, reduces tool wear, increases tool life, and improves surface roughness, especially when machining with high cutting velocity. Moreover. the amount of cutting fluid consumed at the rate of 2 ml/min is a drastic reduction compared to flood application. Also, no harmful oil mist is generated during the pulsed-jet application. In conclusion, the pulsed-jet application can be applied to milling process of hardened steel using ball end mills; it reduces the negative effects to the environment, improves machining performances, and consequently reduces total production cost. (C) 2008 Elsevier Ltd. All rights reserved.
The paper presents a studyof the effect of operating variable parameter; cutting speed, feed rate, depth of cut and width of cut on heat being generated when end milling under MQL condition. The response surface methodology (RSM) was... more
The paper presents a studyof the effect of operating variable parameter; cutting speed, feed rate, depth of cut and width of cut on heat being generated when end milling under MQL condition. The response surface methodology (RSM) was employed in the experiment, and a Box–Behnken design was used to determine the cause and effect of the relationship between the input variables and response. The investigated milling parameters were cutting speed (100 - 140 m/min), feed rate (0.1 - 0.2 mm/tooth), depth of cut (0.5-1.0 mm) and width of cut (0.2 -1.8 mm). Result of this study show ball nose end milling generates low temperature ranging from 69°C to 359°C. Experimental data and statistical analysis showed that heat generation was dominated by radial depth of cut, followed by axial depth of cut. Feed rate and cutting speed were found statistically not significant. The linear models were developed with a 92% confidence level. The optimum condition required for minimum heat generated include cutting speed of 117 m/min, feed rate of 0.11 mm/rev, axial depth of cut of 0.57 mm, and radial depth of cut of 0.21 mm. With this optimum condition, a minimum heat generated of 68°C was obtained.
Now a day the reasons for an increase in the interest to perform machining operations in dry/near-dry environments are health and safety on the cost, operator, ease of chip recyclability, etc. However the important machining process,... more
Now a day the reasons for an increase in the interest to perform machining operations in dry/near-dry environments are health and safety on the cost, operator, ease of chip recyclability, etc. However the important machining process, which is difficult to perform in dry environment, is drilling. Without coolant, drilling leads to high thermal distortion and poor tool life. In order to overcome these conflicts, it is essential to study the machining performances with minimum quantity lubrication (MQL) environment and dry environment. In the present paper Drilling experiments are conducted according to Taguchi L 27 on AL7075-10%SiC p metal matrix composite with uncoated and coated HSS tools under MQL environment. The responses of drilling are analyzed using the Taguchi-Fuzzy model and the best combinations of process parameters are identified.
The paper presents a study of the effect of operating variable parameter; cutting speed, feed rate, depth of cut and width of cut on heat being generated when end milling under MQL condition. The response surface methodology (RSM) was... more
The paper presents a study of the effect of operating variable parameter; cutting speed, feed rate, depth of cut and width of cut on heat being generated when end milling under MQL condition. The response surface methodology (RSM) was employed in the experiment, and a Box–Behnken design was used to determine the cause and effect of the relationship between the input variables and response. The investigated milling parameters were cutting speed (100 - 140 m/min), feed rate (0.1 - 0.2 mm/tooth), depth of cut (0.5-1.0 mm) and width of cut (0.2 -1.8 mm). Result of this study show ball nose end milling generates low temperature ranging from 69°C to 359°C. Experimental data and statistical analysis showed that heat generation was dominated by radial depth of cut, followed by axial depth of cut. Feed rate and cutting speed were found statistically not significant. The linear models were developed with a 92% confidence level. The optimum condition required for minimum heat generated include...
In today's era CNC machines have totally changed the face of the machining process, but a need for a better cooling system has always been sensed. Minimum Quality Lubrication (MQL) system has the potential to be the perfect cooling and... more
In today's era CNC machines have totally changed the face of the machining process, but a need for a better cooling system has always been sensed. Minimum Quality Lubrication (MQL) system has the potential to be the perfect cooling and lubricating system for Computer Numeric Control (CNC) machines by replacing the conventional wet type cooling and lubricating method. This paper talks in detail how MQL system can be implemented in Oil Hole Drilling Machine in Crankshaft production process and its advantages over the conventional wet type cooling and lubricating system.
In this study, a review of the available literature on lubrication techniques during machining processes was conducted. Factors such as workpiece material, tool material and machining conditions were observed to be vital to the... more
Customary mineral based liquids are as a rule broadly utilized in cooling and greases in machining activities. Nonetheless, these cutting liquids are the suitable wellspring of numerous natural and organic issues. To kill the evil impacts... more
Customary mineral based liquids are as a rule broadly utilized in cooling and greases in machining activities. Nonetheless, these cutting liquids are the suitable wellspring of numerous natural and organic issues. To kill the evil impacts related with cutting liquids, it is important to move towards practical machining methods. Such sustainable machining techniques utilize minimize the amount of cutting liquid, fluid nitrogen, vegetable oil or packed air as a cooling-oil medium. The liquids utilized in economical machining strategies are viewed as absolutely biodegradable and Eco-friendly. This paper is a careful survey of the relative multitude of current environmental friendly machining methods as of now rehearsed in the metal cutting cycle. It has been likewise discovered that these economical machining strategies more often than not give better outcomes as far as improved surface nature of the machined part, upgraded apparatus life, less cutting temperatures and slicing powers when contrasted with traditional wet machining techniques. The principle motivation behind this survey work is to recognize the diverse supportable strategies and empower the utilization of such procedures in metal machining, so that, the reducing interaction turns out to be more expense powerful and climate inviting.
