Characterization of Tool–Chip Interface Temperature Measurement With Thermocouple Fabricated Directly on the Rake Face

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Sinan Kesriklioglu ◽  
Cory Arthur ◽  
Justin D. Morrow ◽  
Frank E. Pfefferkorn
Keyword(s):  
Temperature Measurement ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Smart Manufacturing ◽  
Future Research ◽  
Interface Temperature ◽  
Rake Face ◽  
Serrated Chip ◽  
Cutting Insert

The objective of this work is to fabricate thermocouples directly on the rake face of a commercially available tungsten carbide cutting insert for accurately measuring the tool–chip interface temperature during metal cutting. The thermocouples are sputtered onto the cutting insert using micromachined stencils, are electrically isolated with layers of Al2O3, and receive a top coating of AlTiN for durability. The result is a nonsacrificial thermocouple junction that is approximately 1.3 µm below the rake face of the tool and 30 µm from the cutting edge. Experimental and numerical characterization of the temperature measurement accuracy and response time are presented. The instrumented cutting tool can capture the tool–chip interface temperature transients at frequencies of up to 1 MHz, which enables the observation of serrated chip formation and adiabatic shear events. Temperature measurements from oblique machining of 4140 steel are presented and compared with three-dimensional, transient numerical simulations using finite element analysis, where cutting speed and feed are varied. This method of measuring the tool–chip interface temperature shows promise for future research and smart manufacturing applications.

scholarly journals Tool–Chip Interface Temperature Measurement in Interrupted and Continuous Oblique Cutting

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Sinan Kesriklioglu ◽  
Justin D. Morrow ◽  
Frank E. Pfefferkorn
Keyword(s):  
Cutting Tools ◽  
Protective Layer ◽  
Temperature Data ◽  
Interface Temperature ◽  
Rake Face ◽  
Cutting Insert ◽  
Thin Film Thermocouples ◽  
Cutting Experiment ◽  
Aisi 12L14 ◽  
Cutting Speeds

The objective of this work is to fabricate instrumented cutting tools with embedded thermocouples to accurately measure the tool–chip interface temperature in interrupted and continuous turning. Thin-film thermocouples were sputtered directly onto the flat rake face of a commercially available tungsten carbide cutting insert using micromachined stencils and the measurement junction was coated with a protective layer to obtain temperature data 1.3 μm below the tool–chip interface. Oblique interrupted cutting tests on AISI 12L14 steel were performed to observe the influence of varying cutting speeds and cooling intervals on tool–chip interface temperature. An additional cutting experiment was conducted to monitor the interface temperature change between interrupted and continuous cuts.

Investigating the Effect of Cutting Speed Variation on Surface Roughness of 7136 Aluminum Alloy in End Milling

2015 ◽  
Vol 809-810 ◽  
pp. 129-134 ◽  
Author(s):  
Alina Bianca Bonţiu Pop ◽  
Mircea Lobonţiu
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Metal Cutting ◽  
End Milling ◽  
Cutting Speed ◽  
Processing Parameters ◽  
Milling Process ◽  
Future Research ◽  
Cutting Depth ◽  
Speed Variation

Surface quality is affected by various processing parameters and inherent uncertainties of the metal cutting process. Therefore, the surface roughness anticipation becomes a real challenge for engineers and researchers. In previous researches [1] I have investigated the feed rate influence on surface roughness and manufacturing time reduction. The 7136 aluminum alloy was machined by end milling operation using standard tools for aluminum machining. The purpose of this paper is to identify by experiments the influence of cutting speed variation on surface roughness. The scientific contribution brought by this research is the improvement of the end milling process of 7136 aluminum alloy. This material is an aluminum alloy developed by Universal Alloy Corporation and is used in the aircraft industry to manufacture parts from extruded profiles. The research method used to solve the problem is experiment. A range of cutting speeds was used while the cutting depth and the feed per tooth were constrained per minimum and maximum requirements defined for the given cutting tool. The experiment was performed by using a 16 mm End milling cutter, holding two indexable cutting inserts. The machine used for the milling tests was a HAAS VF2 CNC. The surface roughness (response) was measured by using a portable surface roughness tester (TESA RUGOSURF 20 Portable Surface Finish Instrument). Following the experimental research, results were obtained which highlight the cutting speed influence on surface roughness. Based on these results we created roughness variation diagrams according to the cutting speed for each value of feed per tooth and cutting depth. The final results will be used as data for future research.

scholarly journals Strain Rate of Metal Deformation in the Machining Process from a Fluid Flow Perspective

2020 ◽  
Vol 10 (9) ◽  
pp. 3057
Author(s):  
Keguo Zhang ◽  
Keyi Wang ◽  
Zhanqiang Liu ◽  
Xiaodong Xu
Keyword(s):  
Fluid Flow ◽  
Strain Rate ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Shear Plane ◽  
Cutting Process ◽  
Machining Process ◽  
Rake Face ◽  
Metal Deformation

Metal cutting speeds are getting faster with the development of high-speed cutting technology, and with the increase in cutting speed, the strain rate will become larger, which makes the study of the metal cutting process more inconvenient. At the same time, with the increase in strain rate, the dislocation movement controlling the plastic deformation mechanism of metal will change from thermal activation to a damping mechanism, which makes the metal deformation behave more like a fluid. Therefore, it is necessary to explore new ways of studying machining from the perspective of fluid flow. Based on this, a fluid model of the metal cutting process is established, and a method for calculating the strain rate is proposed from the point of view of flow. The results of the simulation and measurements are compared and analyzed. The results show that the strain rate on the rake face will be affected by the friction between the chip and tool; the nearer the distance between the chip layer and tool rake face, the bigger the strain rate will be. The strain rate in the central shear plane is much larger than in other areas along the shear plane direction, and in which two ends are the biggest. It can achieve rougher, quantitative research. This shows it is feasible to study machining from the viewpoint of fluid flow, though it still needs a lot of theoretical support and experimental confirmation.

Tool-Chip Interface Temperature Measurement in Interrupted and Continuous Oblique Cutting

2017 ◽  
Author(s):  
Sinan Kesriklioglu ◽  
Justin D. Morrow ◽  
Frank E. Pfefferkorn
Keyword(s):  
Cutting Tools ◽  
Protective Layer ◽  
Temperature Data ◽  
Interface Temperature ◽  
Rake Face ◽  
Cutting Insert ◽  
Thin Film Thermocouples ◽  
Cutting Experiment ◽  
Aisi 12L14 ◽  
Cutting Speeds

The objective of this work is to fabricate instrumented cutting tools with embedded thermocouples to accurately measure the tool-chip interface temperature in interrupted and continuous turning. Thin-film thermocouples were sputtered directly onto the flat rake face of a commercially available tungsten carbide cutting insert using micro machined stencils and coated the measurement junction with a protective layer to obtain temperature data 1.3 μm below the tool-chip interface. Oblique interrupted cutting tests on AISI 12L14 steel were performed to observe the influence of varying cutting speeds and cooling intervals on tool chip interface temperature. An additional cutting experiment was conducted to monitor the interface temperature change between interrupted and continuous cuts.

The influences of adiabatic shear evolution on tool failure in high-speed machining of railway steel

2018 ◽  
Vol 233 (5) ◽  
pp. 1588-1593
Author(s):  
Liyao Gu
Keyword(s):  
High Speed ◽  
Shear Fracture ◽  
Coupling Effect ◽  
White Layer ◽  
Cutting Speed ◽  
Adiabatic Shear ◽  
High Speed Machining ◽  
Rake Face ◽  
Serrated Chip ◽  
Tool Failure

Adiabatic shear evolution in serrated chip will lead to inevitable impacts on the tool failure with the cutting speed increasing. The high-speed machining experiment of railway steel was carried out by applying the cemented carbide insert. The chip morphology transformation with white layer during adiabatic shear evolution was observed, and its influence on the tool failure mechanism on rake face was further investigated microscopically. The experimental results were concluded that the isolated segment chip formation due to adiabatic shear fracture weakened the wear effects on the rake face under higher cutting speed. The periodical cycle from adiabatic shear banding to fracture which resulted in a thermal–mechanical coupling effect mainly influenced the rake face failure mechanisms.

Prediction of Tool-Chip Interface Temperature in Cryogenic Machining of Ti–6Al–4V: Analytical Modeling and Sensitivity Analysis

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Sinan Kesriklioglu ◽  
Frank E. Pfefferkorn
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
Liquid Nitrogen ◽  
Flow Rate ◽  
Cutting Speed ◽  
Design Parameters ◽  
Interface Temperature ◽  
Cryogenic Machining ◽  
Cooling Strategy ◽  
Cutting Insert

Abstract The goal of this work is to predict the tool-chip interface temperature during cryogenic machining and determine the effectiveness of this cooling strategy. Knowledge of the tool-chip interface temperature is needed to conduct process planning: choosing a tool cooling geometry, cutting speed, and cryogen flow rate as well as predicting tool life and achievable material removal rate. A detailed explanation of the analytical heat transfer model is presented, which is a modified form of Loewen and Shaw's orthogonal cutting model, where a thermal resistance network is applied to represent the heat transfer mechanisms in, and out of, the cutting tool. An in-depth discussion of the temperature rise at the tool-chip interface during orthogonal machining of titanium alloy Ti–6Al–4V is presented. The effect of cutting speed, cryogen flow rate and quality, and cooling strategy are explored. The model is used to compare the effect of internal cryogenic cooling with external flood cooling using a water-based metalworking fluid or liquid nitrogen. A sensitivity analysis of the model is conducted and ranks the relative importance of various design parameters. The thermal conductivity of the cutting insert has the greatest influence on the predicted interface temperature. The low boiling temperature and phase change are what make internal cooling of a cutting insert with liquid nitrogen effective at reducing the tool-chip interface temperature. If the heat flowing into the tool, from the tool-chip interface, does not exceed the available latent heat in the cryogen, then this method is more effective than external flood cooling.

An Analytical Model for Prediction of Tool Temperature Fields during Continuous and Interrupted Cutting

1994 ◽  
Vol 116 (2) ◽  
pp. 135-143 ◽  
Author(s):  
R. Radulescu ◽  
S. G. Kapoor
Keyword(s):  
Analytical Model ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Time History ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Interface Temperature ◽  
Tool Temperature ◽  
Interrupted Cutting

An analytical model for prediction of tool temperature fields in metal cutting processes is developed. The model can be applied to any continuous or interrupted three-dimensional cutting process. To accurately represent the heating and cooling cycles encountered during interrupted cutting, the analysis predicts time dependent heat fluxes into the cutting tool. A time history of this heat flux is obtained by performing an energy balance on the chip formation zone. The variation with time of the tool temperature fields is determined from a heat transfer analysis with prescribed heat generation rate. The analysis requires the cutting forces as inputs. The model tool-chip interface temperatures agree well with the experimental tests reported in the literature, for all cutting conditions and work materials investigated. The results indicate that the tool-chip interface temperature increases with cutting speed during both continuous and interrupted cutting.

Experimental and FEM Study of Serrated Chip Formation in High Speed Turning Processes

2011 ◽  
Vol 264-265 ◽  
pp. 1021-1026
Author(s):  
U. Umer ◽  
Li Jing Xie ◽  
Syed Jawid Askari ◽  
S.N. Danish ◽  
S.I. Butt
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Serrated Chip ◽  
High Speed Turning ◽  
Serrated Chip Formation

The finite element method (FEM) has been used to model high speed turning processes with orthogonal cutting conditions. In most of the situations, continuous chip formation is used to analyze the turning process due to its stability and allowing many conditions to simplify the process. However with the increasing applications of high speed turning, serrated chip formation is becoming a more common phenomenon in metal cutting. Serrated chips usually occur in machining of difficult to cut materials at or above a threshold speed. An updated Lagrangian formulation has been used in this study which works with element deletion technique based on a failure criterion. The Johnson Cook strain-hardening thermal-softening material model is used to model serrated chip formation. In addition high speed turning experiments were conducted on AISI H13 tubes using PCBN to analyze serrated chip phenomenon. The chips were analyzed after surface treatment using scanning electron microscope. It has been found that the length of cuts in the chip increases with the cutting speed and the chip changes from serrated to discontinuous. Different process variables like cutting forces, chip morphology, stress, strain and temperature distributions are predicted at different process parameters using FEM. The results show cyclic variation in the cutting forces at high cutting speeds due to varying chip load.

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.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

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