Performance of Nitrogen and Liquid Nitrogen as Coolants in Orthogonal Machining of AISI 1020 Steel Alloy With Uncoated Carbide Tools

2014 ◽  
Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton ◽  
Wesley Scott Hunko
Keyword(s):  
Liquid Nitrogen ◽  
Chip Thickness ◽  
Statistical Design ◽  
Optical Microscope ◽  
Depth Of Cut ◽  
Steel Alloy ◽  
Metal Working ◽  
Working Fluids ◽  
Orthogonal Machining ◽  
Force Data

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.

Cutting Forces With 3-D Tool Wear Analysis in Orthogonal Tube Machining of 6061-T6 Aluminum Alloy With Uncoated Carbide Tool Inserts Using Cold Compressed Air Versus Liquid Nitrogen as Metal Working Fluids

2015 ◽  
Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton ◽  
Wesley S. Hunko
Keyword(s):  
Aluminum Alloy ◽  
Liquid Nitrogen ◽  
Cutting Forces ◽  
Compressed Air ◽  
Working Fluid ◽  
Carbide Tool ◽  
Metal Working ◽  
Factor Level ◽  
Working Fluids ◽  
Force Data

Metal working fluids remain in common use throughout many industries where metal cutting is necessary. Optimizing the use of a metal working fluid must balance environmental needs, production needs and economic needs. An orthogonal tube turning machining experiment on 6061-T6 aluminum alloy was conducted to study the performance of uncoated carbide tool inserts utilizing cold compressed air and liquid nitrogen environments as the metal working fluid of choice. The tool inserts selected for this study did not have any chip breaker and studied at 3 different rake angles of 0°, 7° and 15°. Aluminum alloy 6061-T6 was used because of its commercially dominant availability and usage. Cold cryogenic cooling was selected because of its growing usage in high performance machining applications. The use of cold compressed air has been much less studied in the machining of metals than in the machining of plastics and composites where it is quite commonly used. The comparisons between these two methods represent the first published values comparing the current extremes of gaseous metal working fluid applications in a commercially dominant aluminum alloy. This statistically designed experiment produced a large amount of comparative data that focused on the wear of the tools in two different cutting environments allowing for multivariate analysis of variance and regressive curve fitting. The orthogonal tube turning was set up on a conventional two axis HAAS TL-2 CNC tool room lathe. Forces were collected utilizing a standard Kistler force dynamometer to record the force data in X, Y and Z axes. Two levels of uncut chip thickness, 0.002” and 0.004” per revolution were maintained with a constant feed and depth of cut of 0.125”. Tool rake angles and depth of cuts were selected to ensure maximum statistical power / decisiveness of the experiment. The experiment was carried out for duration of 1 minute while the force data was collected for the entire duration of cut. New tool insert was used for each factor level combination. The traditional force analysis results are provided for an orthogonal tube turning experiment. In addition, all tools were analyzed for 3-dimensional rake face wear using an innovative Keyence white light microscope in conjunction with a Dektak surface profilometer. Although cutting forces were statistically the same, the inexpensive, simple cold compressed air produced less rake wear than the more expensive liquid nitrogen for all cutting factor level combinations. There was no measureable benefit in using the more expensive liquid nitrogen system.

Multivariate Analysis of Orthogonal Tube Cutting Forces With 3-D Tool Wear Analysis of AISI 1020 Alloy Steel Using Cold Compressed Air Versus Liquid Nitrogen as Metal Working Fluids

2015 ◽  
Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton ◽  
Wesley S. Hunko
Keyword(s):  
Multivariate Analysis ◽  
Liquid Nitrogen ◽  
High Speed ◽  
High Speed Steel ◽  
Compressed Air ◽  
Working Fluid ◽  
Metal Working ◽  
Factor Level ◽  
Working Fluids ◽  
Force Data

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 machining experiment on AISI 1020 alloy steel was conducted to study the performance of High Speed Steel (HSS) tool inserts and carbide tool inserts utilizing cold compressed air and liquid nitrogen environments as the metal working fluid of choice The use of both high speed steel and carbide inserts allowed for direct comparison of geometrically identical inserts in customized tool holders that were used to present the tools with the geometrically identical tool rake angle alpha. Tool holder stiffness was therefore common to all tool rake angles compared. AISI 1020 steel was used because of its commercially dominant availability and usage. Cold cryogenic cooling was selected because of its growing usage in high performance machining applications. The use of cold compressed air has been much less studied in the machining of metals than in the machining of plastics and composites where it is quite commonly used. The comparisons between these two methods represent the first published values comparing the current extremes of gaseous metal working fluid applications in a commercial steel. This statistically designed experiment produced a large amount of comparative data that focused on the wear of the tools in two different cutting environments allowing for multivariate analysis of variance and regressive curve fitting. The orthogonal tube turning was set up on a conventional two axis HAAS TL-2 CNC tool room lathe. Forces were collected utilizing a standard Kistler force dynamometer to record the force data in X, Y and Z axes. Two levels of uncut chip thickness, 0.002 and 0.004” per revolution were maintained with a constant feed and depth of cut of 0.125” at different tool rake angles of 0°, 7° and 15°, with no chip breaker installed in the tool. Tool rake angles and depth of cuts were selected to ensure maximum statistical power/decisiveness of the experiment. The experiment was carried out for duration of 1 minute while the force data was collected for the entire duration of cut. New tool insert was used for each factor level combination. The traditional force analysis results are provided for an orthogonal tube turning experiment. In addition, all tools were analyzed for 3-dimensional rake face wear using an innovative Keyence white light microscope. Surprisingly, the inexpensive, simple cold compressed air produced less wear than the more expensive liquid nitrogen for all cutting factor level combinations.

Orthogonal Turning of Aluminum 6061 in Liquid Nitrogen Cutting Environment

2014 ◽  
Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton ◽  
Wesley Scott Hunko
Keyword(s):  
Tool Wear ◽  
Liquid Nitrogen ◽  
Hard Turning ◽  
Three Dimensional ◽  
Optical Microscope ◽  
Working Fluid ◽  
Depth Of Cut ◽  
Dry Cutting ◽  
Orthogonal Turning ◽  
Force Data

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.

Numerical Investigation of Two-Dimensional Thermally Assisted Ductile Regime Milling of Brittle Materials

2014 ◽  
Author(s):  
Jianfeng Ma ◽  
Xianchen Ge ◽  
Shuting Lei
Keyword(s):  
Chip Thickness ◽  
Rake Angle ◽  
Depth Of Cut ◽  
Critical Depth ◽  
Uncut Chip Thickness ◽  
Thermal Boundary Conditions ◽  
Orthogonal Machining ◽  
Preheating Temperature ◽  
Ductile Regime Machining ◽  
Critical Depth Of Cut

This study investigates the effects of different variables (preheating temperature, edge radius, and rake angle) on ductile regime milling of a bioceramic material known as nanohydroxyapatite (nano-HAP) using numerical simulation. AdvantEdge FEM Version 6.1 is used to conduct the simulation of 2D milling mimicked by orthogonal machining with varying uncut chip thickness. Thermal boundary conditions are specified to approximate laser preheating of the work material. Based on the pressure-based criterion for ductile regime machining, the dependence of critical depth of cut on cutting conditions is investigated using Tecplot 360. It is found that as uncut chip thickness decreases, the critical depth of cut decreases. In addition, the critical depth of cut increases as the negativity of rake angle and/or preheating temperature increase.

Investigation of the Transition From Plane Strain to Plane Stress in Orthogonal Metal Cutting

2004 ◽  
Author(s):  
Vasant Pednekar ◽  
Vis Madhavan ◽  
Amir H. Adibi-Sedeh
Keyword(s):  
Strain Rate ◽  
Plane Strain ◽  
Plane Stress ◽  
Metal Cutting ◽  
Chip Thickness ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Orthogonal Machining ◽  
Strain And Strain Rate ◽  
Plane Strain Deformation

It is widely known that in practical orthogonal machining experiments, interior sections of the deforming material undergo plane strain deformation whereas material near the side faces of the workpiece undergoes plane stress deformation. This study is aimed at investigating the plane strain to plane stress transition using 3D coupled thermo-mechanical finite element analysis of orthogonal machining. The temperature, stress, strain and strain-rate distributions along different planes of the workpiece are analyzed to obtain estimates of the fraction of material undergoing plane strain deformation for different widths of cut. While it is found that the deformation in the mid-section of the workpiece is close to that observed in 2D plane strain simulations, the deformation along the side faces is quite different from that observed in 2D plane stress simulations, due to the constraint imposed upon the material along the sides by the material in the middle. Though the chip thickness along the sides is smaller than the chip thickness in the middle, the strain, strain-rate, and temperature fields along the side face and mid-section are quite similar. This study confirms that accurate maps of temperature, strain and strain-rate in plane strain deformation can be obtained by observing the side faces. It is found that for the cutting conditions used, a width to depth-of-cut ratio of twenty (not ten, as is commonly assumed) results in a close approximation to plane strain deformation through more than 90% of the width of the work material. For a width to depth-of-cut ratio of ten, significant deviations are observed in the stresses, with respect to their corresponding values in plane strain. Recommendations for the width of cut to depth of cut ratio to be used in experiments for other cutting conditions can be developed based upon similar studies.

Influence of Solid Contaminants in Metal Working Fluids on the Grinding Process

2013 ◽  
Vol 769 ◽  
pp. 61-68 ◽  
Author(s):  
Björn Beekhuis
Keyword(s):  
Machine Tool ◽  
Surface Quality ◽  
Solid Particles ◽  
Machining Process ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Metal Working ◽  
Machined Surface ◽  
Working Fluids ◽  
Abrasive Particles

Metal working fluids (MWF) are widely used in grinding processes to lubricate and to remove the heat and chips from the contact zone. Apart from the chips, abrasive particles from the worn grinding wheel contaminate the metalworking fluid. The solid contaminants, in particular the abrasive particles crumbled from the grinding wheel, are believed to cause several negative effects like for example damaging the guideways of the machine tool. Furthermore, it is assumed that a pronounced interaction of the solid particles and the machined surface will decrease the achievable surface quality of the ground surfaces. Cleaning units are employed within the fluid circuit to prevent failure of the machine tool and to ensure the desired surface quality. The economic efficiency of such cleaning plants cleaning plants depends strongly on the choice of the grade of filtration (the particle size which has to be retained). A grade of filtration which exceeds the actual needs of the machining process adds unnecessary costs for operating the cleaning unit. To enable cost efficient design of filtration units the interaction between solid contaminants and the machining process has to be understood. The results of grinding experiments (face grinding of workpieces made of AISI 52100) confirm a significant increase of the surface waviness when corundum particles are added to the MWF. The underlying effect is an extraordinary tool wear combined with a locally varying effective depth of cut. The excess particles block the pores of the grinding wheel and are transported into the grinding gap. An increasing ratio of the size of solid contaminants and the size of the bonded grains on the wheel accelerates the wear of the tool.

Microscopic Tool Wear in Machining Aluminum 6061 T6 (Cold Compressed Air, Nitrogen and Dry Environments

2013 ◽  
Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton
Keyword(s):  
Tool Wear ◽  
High Speed ◽  
Chip Thickness ◽  
High Speed Steel ◽  
Working Fluid ◽  
Depth Of Cut ◽  
Work Piece ◽  
Labview Software ◽  
Designed Experiment ◽  
Force Data

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.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

Effects of Insert Nose Radius and Processing Cutting Parameter on the Surface Roughness of Aisi 316 Stainless Steel

2010 ◽  
Vol 447-448 ◽  
pp. 51-54
Author(s):  
Mohd Fazuri Abdullah ◽  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Abu Bakar Sulong ◽  
Jaharah A. Ghani
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Finish ◽  
Feed Rate ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Aisi 316

The effects of different cutting parameters, insert nose radius, cutting speed and feed rates on the surface quality of the stainless steel to be use in medical application. Stainless steel AISI 316 had been machined with three different nose radiuses (0.4 mm 0.8 mm, and 1.2mm), three different cutting speeds (100, 130, 170 m/min) and feed rates (0.1, 0.125, 0.16 mm/rev) while depth of cut keep constant at (0.4 mm). It is seen that the insert nose radius, feed rates, and cutting speed have different effect on the surface roughness. The minimum average surface roughness (0.225µm) has been measured using the nose radius insert (1.2 mm) at lowest feed rate (0.1 mm/rev). The highest surface roughness (1.838µm) has been measured with nose radius insert (0.4 mm) at highest feed rate (0.16 mm/rev). The analysis of ANOVA showed the cutting speed is not dominant in processing for the fine surface finish compared with feed rate and nose radius. Conclusion, surface roughness is decreasing with decreasing of the feed rate. High nose radius produce better surface finish than small nose radius because of the maximum uncut chip thickness decreases with increase of nose radius.

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