Orthogonal Turning of Aluminum 6061 in Liquid Nitrogen Cutting Environment

Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton ◽  
Wesley Scott Hunko

Liquid nitrogen is studied as an alternative metal working fluid during the machining of Aluminum 6061-T6 alloy using two different tool materials (HSS and an uncoated carbide). The design of the experiment utilized two feeds (0.002”/rev and 0.004”/rev) with a constant depth of cut (0.125 inch) and 3 different tool rake angles of 0°, 7° and 15°. Force data was collected using Kistler dynometer. Three-dimensional (3D) measurements of the tool wear were analyzed using a 3D Keyence optical microscope in conjunction with a Dektak surface profilometer. When contrasted with dry cutting (hard turning), it was found that the liquid nitrogen increased the tool wear with HSS tools but decreased tool wear using uncoated carbide tools. Effect on cutting forces in all cases was statistically insignificant.

2021 ◽  
Author(s):  
Edmilson Dantas de Lima ◽  
Anderson Clayton Alves De Melo ◽  
Adilson José de Oliveira ◽  
Júlio César Giubilei Milan ◽  
Álisson Rocha Machado

Abstract Hard turning is considered a strong candidate to partially replace grinding in finishing operations. However, as in the grinding operation, hard turning produces high temperatures that contributes to accelerate the cutting tool wear. In order to minimize this effect, cutting fluids can be applied as an alternative, even when PCBN inserts are used as cutting tools. However, there are many drawbacks associated with the use of cutting fluids, particularly those of mineral base, as they are hazardous to the environment. In this context, the need for more eco-friendly cutting fluids is growing and liquid nitrogen (LN2) offers a promising alternative. Previous studies have shown that LN2 can significantly reduce the cutting tool wear rate in comparison with other cooling strategies, and this is normally attributed to a reduction in the tool-chip interface temperature. However, investigations on the tool-chip interface temperature in cryogenic machining are scarce in the literature, particularly with regard to the turning of tool steels, and this study was performed to partially fill this gap. The tool-chip interface temperature during the turning of quenched and tempered AISI D6 tool steel, under dry conditions and using LN2, was investigated. A tool-workpiece thermocouple system was developed for this purpose and calibrated using a data acquisition system based on the low-cost Arduino Uno platform. In the turning tests, liquid nitrogen was delivered at the tool flank face of PCBN inserts at three cutting speeds with a constant feed rate and depth of cut. The results showed that LN2 was effective in reducing the tool-chip interface temperature at the lowest cutting speed; however, when this cutting parameter was increased, the reduction in the interface temperature was minimal as compared with the dry condition.


Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton ◽  
Wesley Scott Hunko

The growing cost associated with insurance, handling and disposing of conventional metal working fluids (oil and water based) continues to drive a need for alternative metal working fluids. An orthogonal tube turning experiment was conducted to study the effects of nitrogen and liquid nitrogen in machining of AISI 1020 steel alloy on a HAAS CNC lathe along with a Kistler Dynamometer to record the force data. Two levels of uncut chip thickness, 0.002” and 0.004” per revolution are maintained with a constant feed and depth of cut of 0.125”. The tool used in this study is an uncoated carbide insert at three different rake angles of 0°, 7° and 15°, with no chip breaker. The statistical design of the experiment established the machining for a duration of 1 minute at each factor level combination. Force data from the dynamometer is analyzed along with wear of the tooling. Tool inserts were studied under a 3-dimensional optical microscope to measure the rake face tool wear. Simple nitrogen produced less wear than the more expensive liquid nitrogen setup.


Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton

The current study is a statistically designed experiment to evaluate different cutting environments that can be used in machining aluminum 6061 T6. High speed steel inserts were used along with different levels of uncut chip thickness in a classic orthogonal tube turning experiment. The cutting fluids used in this study are nitrogen and cold compressed “shop” air that are compared to the results obtained from dry machining. The force data (cutting force and the thrust force) were collected using a Kistler force dynamometer and processed using Labview software. The tools are subjected to 1 minute of cutting at two different feed rates of 0.002″/rev. and 0.004″/rev at a constant depth of cut of 0.125″ and at a constant speed. The tool inserts after 1 minute of cutting are studied for tool wear using a Keyance microscope. The surface finish of the work piece surface (average surface roughness) after one minute of cutting is examined under a Dektak 150 contact type surface profilometer. Alternative metal working fluid options are discussed.


Author(s):  
Amritpal Singh ◽  
Rakesh Kumar

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters in the hard turning of EN36 steel under the dry cutting condition is done. The input control parameters selected for the present work was the cutting speed, feed and depth of cut. The objective of the present work is to minimize the surface roughness to obtain better surface finish and maximization of material removal rate for better productivity. The design of experiments was done with the help of Taguchi L9 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence value. From results, it was observed that feed is the most significant factor for surface roughness and the depth of cut is the most significant control parameter for Material removal rate.


Author(s):  
Mahendran Samykano ◽  
J. Kananathan ◽  
K. Kadirgama ◽  
A. K. Amirruddin ◽  
D. Ramasamy ◽  
...  

The present research attempts to develop a hybrid coolant by mixing alumina nanoparticles with cellulose nanocrystal (CNC) into ethylene glycol-water (60:40) and investigate the viability of formulated hybrid nanocoolant (CNC-Al2O3-EG-Water) towards enhancing the machining behavior. The two-step method has been adapted to develop the hybrid nanocoolant at various volume concentrations (0.1, 0.5, and 0.9%). Results indicated a significant enhancement in thermal properties and tribological behaviour of the developed hybrid coolant. The thermal conductivity improved by 20-25% compared to the metal working fluid (MWF) with thermal conductivity of 0.55 W/m℃. Besides, a reduction in wear and friction coefficient was observed with the escalation in the nanoparticle concentration. The machining performance of the developed hybrid coolant was evaluated using Minimum Quantity Lubrication (MQL) in the turning of mild steel. A regression model was developed to assess the deviations in the tool flank wear and surface roughness in terms of feed, cutting speed, depth of the cut, and nanoparticle concentration using Response Surface Methodology (RSM). The mathematical modeling shows that cutting speed has the most significant impact on surface roughness and tool wear, followed by feed rate. The depth of cut does not affect surface roughness or tool wear. Surface roughness achieved 24% reduction, 39% enhancement in tool length of cut, and 33.33% improvement in tool life span. From this, the surface roughness was primarily affected by spindle cutting speed, feed rate, and then cutting depth while utilising either conventional water or composite nanofluid as a coolant. The developed hybrid coolant manifestly improved the machining behaviour.


2013 ◽  
Vol 6 (3) ◽  
pp. 17-27
Author(s):  
Akeel Ali Wannas

Hard turning technology has been gaining acceptance in many industries throughout the last 2decades. The trend today is to replace the slow and cost-intensive grinding process with finish hard turning in many industrial applications such as bearings, transmission shafts, axles and engine components, flap gears, landing struts and aerospace engine components. In this study, Radial Basis Function Neural Network (RBFNN) model has been developed for the prediction of the status of the tool wear. Learning data was collected from Experimental setup. The neural network model has 3 input nodes and one output representing process Modeling correlates process state variables to parameters. The process input parameters are Feed rate (F), cutting Speed (S) and Depth of cut (Dc). The process output is state Variable (Vb). Regression analysis between finite element results and values predicted by the neural network model shows the least error.


Author(s):  
Krishnaraj Vijayan ◽  
N. Gouthaman ◽  
Tamilselvan Rathinam

The objectives of hard turning of high speed steel (HSS-M2 Grade) are to investigate the effect of cutting parameters on cutting force, tool wear and surface integrity. This article presents the experimental results of heat treated high speed steel machined in a CNC lathe using cubic boron nitride (CBN) tools. Turing experiments were carried out using central composite design (CCD) method. From the experiments the influence of cutting parameters and their interactions on cutting forces, temperature and surface roughness (Ra) were analyzed. Following this, multi response optimization was done to find the best combination of parameters for minimum force, minimum temperature and minimum surface roughness. The experimental results showed that the most contributing factors were feed followed by depth of cut and spindle speed. A white layer formed during hard turning was also analyzed by scanning electron microscope (SEM) and the results showed that it was greatly influenced by the speed and depth of cut. Tool wear was experiments were conducted at the optimum cutting conditions and it was noted that the tool satisfactorily performed up to 10 minutes at dry condition.


Author(s):  
M Jahanbakhsh ◽  
A Akhavan Farid ◽  
Mohammad Lotfi

Rapid tool wear is one of the major machinability aspects of nickel-based super alloys. In this article, the effect of cutting parameters on material removal rate and tool wear of a whisker ceramic insert in turning of Inconel 625 was examined. Optical microscope and scanning electron microscope were applied to measure and study tool wear mechanism. Response surface method was used to develop a mathematical model which confirmed by experimental tests. The statistical analysis done by analysis of variance showed that depth of cut is the most effective factor on the tool wear. Experiments showed that increment of feed rate had an insignificant effect on the progress of flank wear, and it is an important controlling factor when material removal rate is considered as a desired output. Finally, optimized cutting condition is presented in this work.


2014 ◽  
Vol 14 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Suha K. Shihab ◽  
Zahid A. Khan ◽  
Aas Mohammad ◽  
Arshad Noor Siddiquee

AbstractThe cutting parameters such as the cutting speed, the feed rate, the depth of cut, etc. are expected to affect the two constituents of surface integrity (SI), i.e., surface roughness and micro-hardness. An attempt has been made in this paper to investigate the effect of the CNC hard turning parameters on the surface roughness average (Ra) and the micro-hardness (μh) of AISI 52100 hard steel under dry cutting conditions. Nine experimental runs based on an orthogonal array of the Taguchi method were performed and grey relational analysis method was subsequently applied to determine an optimal cutting parameter setting. The feed rate was found to be the most influential factor for both the Ra and the μh. Further, the results of the analysis of variance (ANOVA) revealed that the cutting speed is the most significant controlled factor for affecting the SI in the turning operation according to the weighted sum grade of the surface roughness average and micro-hardness.


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