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.

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.

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.

scholarly journals Influence of metal working fluid on chip formation and mechanical loads in orthogonal cutting

2021 ◽  
Author(s):  
Berend Denkena ◽  
Alexander Krödel ◽  
Lars Ellersiek
Keyword(s):  
Chip Formation ◽  
High Speed ◽  
Orthogonal Cutting ◽  
Machining Process ◽  
Working Fluid ◽  
Rake Face ◽  
Metal Working ◽  
Mechanical Loads ◽  
Working Fluids ◽  
Process Forces

AbstractMetal working fluids are used in machining processes of many hard-to-cut materials to increase tool life and productivity. Thereby, the metal working fluids act on the thermal and on the mechanical loads of the tool. The changing mechanical loads can mostly be attributed to the changing friction between rake face and chip and changes in the chip formation, e.g., the contact length between rake face and chip. However, analyzing those effects is challenging, since a detailed look at the chip formation process is prevented by the metal working fluid. In this paper, a novel planing test rig is presented, which enables high-speed recordings of the machining process and process force measurements while using metal working fluids. Experiments reveal that process forces are reduced with increasing pressure of the metal working fluid. However, the average friction coefficient only changes slightly, which indicates that the reduced process forces are mainly the result of reduced contact lengths between rake face and chip.

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.

Siloxanes as Working Fluids for Mini-ORC Systems Based on High-Speed Turbogenerator Technology

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Antti Uusitalo ◽  
Teemu Turunen-Saaresti ◽  
Juha Honkatukia ◽  
Piero Colonna ◽  
Jaakko Larjola
Keyword(s):  
Molecular Weight ◽  
Power Output ◽  
High Speed ◽  
Thermodynamic Cycle ◽  
Turbine Rotor ◽  
Working Fluid ◽  
Specific Enthalpy ◽  
Working Fluids ◽  
Simulated Performance ◽  
Component Design

This paper presents a study aimed at evaluating the use of siloxanes as the working fluid of a small-capacity (≈10kWe) ORC turbogenerator based on the “high-speed technology” concept, combining the turbine, the pump, and the electrical generator on one shaft, whereby the whole assembly is hermetically sealed, and the bearings are lubricated by the working fluid. The effects of adopting different siloxane working fluids on the thermodynamic cycle configuration, power output, and on the turbine and component design are studied by means of simulations. Toluene is included into the analysis as a reference fluid in order to make comparisons between siloxanes and a suitable low molecular weight hydrocarbon. The most influential working fluid parameters are the critical temperature and pressure, molecular complexity and weight, and, related to them, the condensation pressure, density and specific enthalpy over the expansion, which affect the optimal design of the turbine. The fluid thermal stability is also extremely relevant in the considered applications. Exhaust gas heat recovery from a 120 kW diesel engine is considered in this study. The highest power output, 13.1 kW, is achieved with toluene as the working fluid, while, among siloxanes, D4 provides the best simulated performance, namely 10.9 kW. The high molecular weight of siloxanes is beneficial in low power capacity applications, because it leads to larger turbines with larger blade heights at the turbine rotor outlet, and lower rotational speed if compares, for instance, to toluene.

Centrifugal Compressor Working Fluids for Refrigeration Cycle

2009 ◽  
Author(s):  
Pekka Ro¨ytta¨ ◽  
Juha Honkatukia ◽  
Teemu Turunen-Saaresti
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Working Fluid ◽  
Accurate Estimation ◽  
Cooling Power ◽  
Condensation Temperature ◽  
Refrigeration Cycle ◽  
Light Weight ◽  
Centrifugal Compressors ◽  
Working Fluids

A centrifugal high-speed compressor is an effective light weight option to power a refrigeration cycle for air conditioning purposes. Perhaps the most important decision in design is the working fluid selection. Modern high-speed technology makes it possible for the refrigeration compressor to be completely oil free, which considerably broadens the scale of possible working fluids. Furthermore, many traditional fluids have become banned and the industry standard R134a might face the same faith in some European countries because of its relatively high global warming potential. In this study eleven different fluids were studied and compared and R22 was used as a reference. It was found that there are many potential fluids for centrifugal compressors that provide better efficiencies than the most common fluids in use today. The purpose of this study is to initially screen a larger set of candidate fluids for more accurate estimation later on. The fluids are evaluated by the efficiency of the cycle, but also mechanical feasibility and dimensions are considered as light weight of the machinery was an important criterion in design process. The comparison was made with constant evaporation and condensation temperature and fixed cooling power for all the fluids. In selection of the working fluid the safety factors often play a dominant role which was also shortly considered. In our study we found out that for a residential HVAC size cooling cycle there are environmentally friendly fluids with high efficiency leading to feasible mechanical designs with centrifugal compressors.

Development of a New Tool Material to Ensure High Performance in Hot Steel Rolling

1999 ◽  
Vol 121 (4) ◽  
pp. 739-745
Author(s):  
Kenji Tsubouchi ◽  
Masayoshi Akiyama ◽  
Eiji Yamamoto ◽  
Toshiro Mase
Keyword(s):  
Tool Life ◽  
High Speed ◽  
High Performance ◽  
Tool Material ◽  
High Speed Steel ◽  
Structure Design ◽  
Metal Working ◽  
Hot Metal ◽  
Steel Rolling ◽  
Tool Surface

A new structure design was presented to prolong the tool life for hot metal working. The tool surface deteriorates quickly when attacked under continuous severe sliding conditions by hot metal at a temperature above 1473 K. Observations were made on guide shoes used in seamless tube rolling to reach the conclusion that enlargement of the size and change in the structure of chromium carbide prolong the tool life. This is contrary to the structure design of high-speed steel for which small carbide is recommended. The validity of the new tool was verified both in laboratory tests and in the production line.

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.

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