scholarly journals Modelling and prediction of cutting temperature in the machining of H13 hard steel of multi-layer coated cutting tools

2021 ◽  
Author(s):  
Jingjie Zhang ◽  
Zhanqiang Liu ◽  
Chonghai Xu ◽  
Jin Du ◽  
Guosheng Su ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Simulated Data ◽  
Analytical Models ◽  
Interface Temperature ◽  
Transfer Model ◽  
Process Data ◽  
Mono Layer ◽  
Coated Tools

Abstract The coating effect on the cutting temperature has long been a hot topic in understanding heat transfer mechanism in machining coated tools, and especially the multi-layer coated tools. For multi-layer coated tools, the coating structure, coating thickness and coating material will affect the cutting temperature of the tool. This paper is devoted to the cutting temperature in dry turning of H13 hardened steel with multi-layer coatings. New analytical models for estimating coating temperature and coating-substrate interface temperature were proposed. The multi-layer coating can be equivalent to mono-layer composite coating, which applies equivalent coating layer approach, and was developed to estimate the cutting temperature in turning by heat transfer model of mono-layer coated tool. The analyzed results were compared to appropriate experimental process data using thermocouples and FEM simulated data. The models were verified can accurate temperature under the same cutting conditions for two multi-layer coated tools.

scholarly journals Conjugate heat transfer performance of stepped lid-driven cavity with Al2O3/water nanofluid under forced and mixed convection

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Naveen Janjanam ◽  
Rajesh Nimmagadda ◽  
Lazarus Godson Asirvatham ◽  
R. Harish ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mixed Convection ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Performance ◽  
Pure Water ◽  
Interface Temperature ◽  
Transfer Model ◽  
Transfer Performance ◽  
Driven Cavity

AbstractTwo-dimensional conjugate heat transfer performance of stepped lid-driven cavity was numerically investigated in the present study under forced and mixed convection in laminar regime. Pure water and Aluminium oxide (Al2O3)/water nanofluid with three different nanoparticle volume concentrations were considered. All the numerical simulations were performed in ANSYS FLUENT using homogeneous heat transfer model for Reynolds number, Re = 100 to 500 and Grashof number, Gr = 5000, 13,000 and 20,000. Effective thermal conductivity of the Al2O3/water nanofluid was evaluated by considering the Brownian motion of nanoparticles which results in 20.56% higher value for 3 vol.% Al2O3/water nanofluid in comparison with the lowest thermal conductivity value obtained in the present study. A solid region made up of silicon is present underneath the fluid region of the cavity in three geometrical configurations (forward step, backward step and no step) which results in conjugate heat transfer. For higher Re values (Re = 500), no much difference in the average Nusselt number (Nuavg) is observed between forced and mixed convection. Whereas, for Re = 100 and Gr = 20,000, Nuavg value of mixed convection is 24% higher than that of forced convection. Out of all the three configurations, at Re = 100, forward step with mixed convection results in higher heat transfer performance as the obtained interface temperature is lower than all other cases. Moreover, at Re = 500, 3 vol.% Al2O3/water nanofluid enhances the heat transfer performance by 23.63% in comparison with pure water for mixed convection with Gr = 20,000 in forward step.

Identification for Control of Low Pressure Die Casting

2010 ◽  
Author(s):  
XinMei Shi ◽  
Daan M. Maijer ◽  
Guy Dumont
Keyword(s):  
Heat Transfer ◽  
State Space ◽  
Die Casting ◽  
State Space Model ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Process Data ◽  
Space Model ◽  
Model Based ◽  
Virtual Process

Controlling and eliminating defects, such as macro-porosity, in die casting processes is an on-going challenge for manufacturers. Current strategies for eliminating defects focus on the execution of a pre-set casting cycle, die structure design or the combination of both. To respond to process variability and mitigate its negative effects, advanced process control methodologies may be employed to dynamically adjust the operational parameters of the process. In this work, a finite element heat transfer model, validated by comparison with experimental data, has been developed to predict the evolution of temperatures and the volume of liquid encapsulation in an experimental casting process. A virtual process, made up of the heat transfer model and a wrapper script for communication, has been employed to simulate the continuous operation of the real process. A stochastic state-space model, based on data from measurements and the virtual process, has been developed to provide a reliable representation of this virtual process. The parameters of the deterministic portion result from system identification of the virtual process, whereas the parameters of the stochastic portion arise from the analysis and comparison of measurement data with virtual process data. The resulting state-space model, which can be extended to a multi-input multi-output model, will facilitate the design of a model-based controller for this process.

Finite Element Investigation of Cutting Performance of Cr/W-DLC/DLC Composite Coated Cutting Tool

2021 ◽  
Author(s):  
Tianmei Hao ◽  
Jin Du ◽  
Xue Zhang ◽  
Guosheng Su ◽  
Peirong Zhang ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Cutting Force ◽  
Cutting Tool ◽  
Cutting Temperature ◽  
Cutting Performance ◽  
Interface Temperature ◽  
Machined Surface ◽  
Heat Partition ◽  
Coated Tools ◽  
Cutting Deformation

Abstract Coupled with a thermo-mechanical metal cutting process, rapid tool wear, higher surface roughness and mass heat are caused by the rapid plastic deformation of the workpiece and by the friction along the tool-chip interface. This phenomenon is more predominant in the machining of difficult-to-cut materials. DLC film has been applied as coating material in the machining of difficult-to-cut materials, and shows a good cutting performance. In this study, Cr/W-DLC/DLC coated tools were compared with other three coated tools (i.e., TiC-, TiAlN-, Al 2 O 3 -) to investigate the cutting performance in the machining of Al-Si alloy (AC9B). In addition, the influence of Cr/W-DLC/DLC coated tools on the cutting performance under different cutting speeds was studied. Cutting force, cutting temperature, heat transfer coefficient of the rake face of the tool, cutting deformation rate, plastic deformation of machined surface, the interface temperature and stress were investigated numerically based on Finite Element Method (FEM). Actual cutting experiments were carried out to the verification of the FEM models by means of the cutting force and cutting temperature measurement. The investigation results showed that Cr/W-DLC/DLC coated tools has the lowest cutting force and cutting temperature, good cutting deformation characteristics and lower coating-substrate interface temperature and stress, however appears the maximum value of heat partition coefficient into the cutting tool. With the increasing of cutting speeds, cutting force and cutting temperature showed an increase trend, while the plastic deformation depth of machined surface and heat partition into cutting tool all showed a decrease trend. This investigation can provide the theory basis or technical guidance for the cutting practice of Cr/W-DLC/DLC coated tools.

Experiment on Optimal Selecting for Cutting Tools in Milling of High Hardened Steel

2012 ◽  
Vol 723 ◽  
pp. 305-310
Author(s):  
Kun Peng Zhang ◽  
Cheng Yong Wang ◽  
Y.N. Hu ◽  
Y.X. Song
Keyword(s):  
Cutting Tools ◽  
Cutting Temperature ◽  
High Hardness ◽  
Hardened Steel ◽  
Tool Geometry ◽  
Coated Tools ◽  
Processing Cost ◽  
Cutting Vibration ◽  
Milling Characteristics ◽  
Cutting Experiments

In this paper, with milling characteristics of high hardness hardened steel, we choice six different coated tools to made cutting experiments on high hardness hardened steel Cr12MoV (HRC65). In this stage, through the analysis of cutting force, cutting temperature, cutting vibration, machined quality and tool wear, we have elected the preferred tool and tool geometry parameters for this processing stage. The results of the study show that: TiAlSiN is the most suitable for Cr12MoV (HRC65), which helps to improve cutting processing productivity, prolong tool life, and enhance processing quality and reduce the processing cost.

scholarly journals Machining temperature comparative analysis of end mill and novel tool in orbital drilling of CFRP composite

2021 ◽  
Author(s):  
Linghao Kong ◽  
Dong Gao ◽  
Yong Lu
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Polar Coordinates ◽  
Transfer Model ◽  
Processing Temperature ◽  
The Novel ◽  
Differential Heat ◽  
Cutting Force Prediction ◽  
Orbital Drilling

Abstract Applying Carbon fiber-reinforced plastics (CFRPs) instead of traditional materials can improve the structural strength and reduce the weight of the spacecraft. However, the defects and the rejections still impede the wide application of CFRP for the contrasting thermo-mechanical properties of fibers and resin. A lower machining temperature can reduce burrs and delamination effectively. To study the cutting temperature of orbital drilling in CFRP, the processing temperature of the conventional orbital drilling (COD) was compared with the novel orbital drilling and reaming tool (ODR), and a heat transfer model considering the influence of convective heat transfer on cutting temperature was also proposed in this research, which can explain the reason of the novel tool with a lower cutting temperature. On the basis of the analysis of the kinematic mechanisms, a cutting force prediction model for the process of orbital drilling was presented. The three-dimensional, unsteady state, nonhomogeneous partial differential heat transfer equation in polar coordinates was established, and solved with the finite difference approach. The results show that the predictions of models are coincided to the experimental data, and ODR tool can reduce the processing temperature of orbital drilling effectively.

A Two-Dimensional Transient Thermal Model for Coated Cutting Tools

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Coskun Islam ◽  
Yusuf Altintas
Keyword(s):  
Heat Transfer ◽  
Sliding Friction ◽  
Cutting Tools ◽  
Surface Zone ◽  
Rake Face ◽  
Discrete Elements ◽  
Workpiece Surface ◽  
Coated Tools ◽  
Part Surface ◽  
Transient Thermal

Prediction of temperature in the tool, chip, and workpiece surface is important to study tool wear, residual stresses in the machined part, and to design cutting tool substrates and coating. This paper presents a finite difference method-based prediction of temperature distribution in the tool, chip, and workpiece surface for transient conditions. The model allows inclusion of anisotropic materials such as coating or different material properties. The energy is created in the primary shear zone where the metal is sheared, the secondary deformation zone where the chip moves on the tool rake face with friction, and the tertiary zone where the flank face of the tool rubs against the finished part surface. The model allows both sticking and sliding friction contact of the moving chip on the rake face of the tool. The distribution of temperature is evaluated by meshing chip, workpiece surface zone, and tool into small discrete elements. The heat transfer among the elements is modeled, and the temperature is predicted at the center of each element. The heat transfer to the tool, workpiece, and chip is iteratively evaluated. The predicted temperature values are compared against the experimental measurements collected with coated tools in turning.

Heat Conduction Analysis of Coated Cutting Tools with Temperature-Dependent Properties

2009 ◽  
Vol 69-70 ◽  
pp. 389-393 ◽  
Author(s):  
S.J. Zhang ◽  
Zhan Qiang Liu
Keyword(s):  
Heat Conduction ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Temperature Dependent ◽  
Machined Surface ◽  
Average Temperature ◽  
Coated Tools ◽  
Temperature Dependent Properties ◽  
Cutting Processes

The heat generation during metal cutting processes affects accuracy of the machined surface and strongly influences cutting forces and tool wear. Material property of coated tools is one of the most important factors effecting heat conduction and temperature on the rake face of coated tools. To find the action of thermal properties of coated cutting tools on cutting temperature, the temperature distributions were obtained with temperature-dependent properties and temperature-independent properties of coated tools using numerical method. The results indicated that temperature-dependent properties should be considered when calculating cutting temperature. To simplify calculation, selecting the thermal conductivities at average temperature to substitute for temperature-dependent properties can reduce calculating error. The conclusion provides a methodology for analysis of cutting temperature of coated tools, design of cutting tools and analysis of thermal stress within coated tools in manufacturing industries.

Theoretical Post-Dryout Heat Transfer Model

2018 ◽  
Vol 1 (1) ◽  
pp. 142-150
Author(s):  
Murat Tunc ◽  
Ayse Nur Esen ◽  
Doruk Sen ◽  
Ahmet Karakas
Keyword(s):  
Heat Transfer ◽  
Droplet Diameter ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Operating Pressure ◽  
Vertical Pipe ◽  
Two Phase ◽  
Experimental Values ◽  
Reactor Operating ◽  
Coolant System

A theoretical post-dryout heat transfer model is developed for two-phase dispersed flow, one-dimensional vertical pipe in a post-CHF regime. Because of the presence of average droplet diameter lower bound in a two-phase sparse flow. Droplet diameter is also calculated. Obtained results are compared with experimental values. Experimental data is used two-phase flow steam-water in VVER-1200, reactor coolant system, reactor operating pressure is 16.2 MPa. On heater rod surface, dryout was detected as a result of jumping increase of the heater rod surface temperature. Results obtained display lower droplet dimensions than the experimentally obtained values.

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