Evaluation of Thermal Effects in Turning Processes: Numerical and Experimental Approach

2019 ◽  
Author(s):  
Aruna Prabha Kolluri ◽  
Srinivasa Prasad Balla ◽  
Satya Prasad Paruchuru
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Tool Wear ◽  
Wear Mechanism ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Tool Material ◽  
Maximum Error ◽  
Tool Wear Mechanism ◽  
Coated Carbide

Abstract The 3D Finite element method (FEM) is an efficient tool to predict the variables in the cutting process, which is otherwise challenging to obtain with the experimental methods alone. The present study combines both experimental findings and finite element simulation outcomes to investigate the effect of tool material on output process variables, such as vibrations, cutting temperature distribution and tool wear mechanism. Machining of popular aerospace materials like Ti-6Al-4V and Al7075 turned with coated and uncoated tools are part of the investigation. The authors choose the orthogonal test, measured vibrations and cutting temperatures and used FE simulations to carry out the subsequent validations. This study includes the influence of the predicted heat flux and temperature distribution on the tool wear mechanism. The main aim of this study is to investigate the performance quality of uncoated and coated carbide tools along with its thermal aspects. Comparison of experiment and simulation outcomes shows good agreement with a maximum error of 9.02%. It has been noted that the increase of cutting temperature is proportional to its cutting speed. As the cutting speed increases, it is observed that vibration parameter and flank wear value also increases. Overall, coated carbide turning insert tool is the best method for metal turning with higher rotational speeds of the spindle.

Material Ductile Failure-Based Finite Element Simulations of Chip Serration in Orthogonal Cutting of Titanium Alloy Ti-6Al-4V

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Guoliang Liu ◽  
Suril Shah ◽  
Tuğrul Özel
Keyword(s):  
Finite Element ◽  
Titanium Alloy ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Ductile Failure ◽  
Ductile Deformation ◽  
Ductile Material ◽  
Damage Initiation ◽  
Coated Carbide

Titanium alloy Ti-6Al-4V, an alpha-beta alloy, possesses ductile deformation behavior and offers advantageous properties, light weight but high strength, good resilience, and resistance to corrosion, becoming highly suitable for aerospace and biomedical applications. However, its machinability is still considered a limiting factor in improving productivity. This paper presents a finite element modeling methodology for orthogonal cutting titanium alloy Ti-6Al-4V by considering material constitutive modeling together with material ductile failure in combination with damage initiation and cumulative damage-based evolution to simulate not only ductile material separation from workpiece to form chips but also chip serration mechanism by applying an elastic–viscoplastic formulation. The finite element model is further verified with orthogonal cutting experiments (using both uncoated and TiAlN-coated carbide tools) by comparing simulated and acquired forces and simulated and captured chip images at high cutting speeds. The effects of cutting speed, feed, tool rake angle, and tool coating on the degree of chip serration are studied through the simulation results. The cutting temperature and strain distributions are obtained to study the chip serration mechanism under different cutting conditions. It is confirmed that the material failure, crack initiation, and damage evolution are of great significance in the chip serration in cutting titanium alloy Ti-6Al-4V.

Finite Element Analysis of Ultrasonic Vibration Assisted Turning of Ferrous Metals

2013 ◽  
Vol 567 ◽  
pp. 33-38 ◽  
Author(s):  
Lai Zou ◽  
Ming Zhou
Keyword(s):  
Finite Element ◽  
Tool Wear ◽  
Ultrasonic Vibration ◽  
Single Point ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Diamond Turning ◽  
Depth Of Cut ◽  
Technological Parameters ◽  
Ferrous Metals

Ultrasonic vibration assisted turning has significant improvements in processing of intractable materials compared to conventional turning. This paper presents a theoretical investigation of tool wear in single point diamond turning of ferrous metals based on numerical simulation. Finite element modeling and simulation of ultrasonic vibration turning process were performed, aimed at optimizing a series of technological parameters in the process of machining, reducing tool wear and improving surface quality as much as possible. The results revealed that the cutting speed and depth of cut are two crucial factors for tool wear, unlike the other parameters of vibration frequency, amplitude and flank angle. Moreover, this technological measure has observably decreased the cutting force and cutting temperature, so as to obtain superior surface finish.

The Investigation of Tool Wear in Metal Machining Using Finite Element Method

2009 ◽  
Vol 407-408 ◽  
pp. 395-399
Author(s):  
Hong Yan Ruan ◽  
Hua Yan ◽  
Shu Bin Lu ◽  
Hui Xia Liu ◽  
Xiao Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Tool Wear ◽  
Cutting Speed ◽  
Wear Depth ◽  
Metal Machining ◽  
Tool Wear Mechanism ◽  
Cutting Model ◽  
Cutting Speeds ◽  
Element Method

The existing studies based on 2-dimension cutting model are partial investigations on tool wear. In order to get close to the true cutting conditions, the Lagrangian thermo-viscoplastic cutting simulations were conducted and the tool wears were predicted under different cutting speeds using 3-dimension finite element models. The simulation results indicate that when the cutting speed increases the cutting forces will reduce accordingly while the wear depth will be deeper. As a result, different factors should be considered at the same time when the speed range is selected. This study has shown that the finite element method is a valuable approach to understand the tool wear mechanism in machining and the influences of different cutting speeds.

PCBN Tool Wear Mechanism in Hard Turning Hardened Bearing Steel

2006 ◽  
Vol 315-316 ◽  
pp. 334-338 ◽  
Author(s):  
S.J. Dai ◽  
Dong Hui Wen ◽  
Ju Long Yuan
Keyword(s):  
Wear Mechanism ◽  
Hard Turning ◽  
Cutting Temperature ◽  
Tool Material ◽  
Bearing Steel ◽  
Workpiece Material ◽  
Pcbn Tool ◽  
Wear Pattern ◽  
Tool Wear Mechanism ◽  
Cutting Zone

The wear pattern and mechanism during continuous hard turning GCr15 hardened bearing steel with BZN8200 PCBN cutting tool was studied. Experimental results showed that the main wear pattern is crater wear in rake face and mechanical wear in flank face, the main wear mechanism is made-up with adhesive, oxidization and diffusive wear. The adhesive wear is generated by melt workpiece material flows with binder material of PCBN tool during initial cutting, oxidative wear is derived by cutting temperature and pressure of cutting zone when the flank wear increase after initial cutting, diffusive wear phenomenon is the absolute mechanism with the diffusive effect between workpiece and tool material in final cutting time.

Effect of High Pressure Coolant on Tool Wear Phenomenon during Machining of Titanium Alloy Ti6Al4V

2016 ◽  
Vol 826 ◽  
pp. 93-98 ◽  
Author(s):  
Pravin Pawar ◽  
Sandip Patil ◽  
Swapnil Kekade ◽  
Swapnil Pawar ◽  
Rajkumar Singh
Keyword(s):  
High Pressure ◽  
Tool Wear ◽  
Wear Mechanism ◽  
Chemical Reactivity ◽  
Cutting Temperature ◽  
Machining Process ◽  
Tool Wear Mechanism ◽  
Flank Face ◽  
Titanium Alloy Ti6al4v ◽  
High Pressure Coolant

Titanium alloys are referred to difficult-to-cut materials because of its some inferior properties like low thermal conductivity and high chemical reactivity. To improve machinability of these alloys one way is to use cutting fluids which removes the heat generated at the chip tool interface during the machining process. But coolant with low pressure and improper delivery is not able to break the vapor barrier created by high cutting temperature. The present work investigates the effect of using high pressure coolant system (50 Bar) on machinability of Ti6Al4V. The machinability was measured in terms of tool wear. The dominant tool wear mechanism was investigated by using scanning electron microscopy and energy dispersive X-ray analysis of worn out cutting tool surfaces. Abrasion wear on flank face and crater wear on the rake face was observed as a dominant tool wear mechanism. Along with this diffusion of titanium from the work surface to tool face is also confirmed.

The Thermal Mechanics of Tool Wear

1966 ◽  
Vol 88 (1) ◽  
pp. 93-100 ◽  
Author(s):  
N. H. Cook ◽  
P. N. Nayak
Keyword(s):  
Plastic Deformation ◽  
Tool Wear ◽  
Empirical Evidence ◽  
Wear Mechanism ◽  
Cutting Temperature ◽  
Tool Material ◽  
Simple Theories ◽  
Remarkable Agreement

Empirical evidence is presented to show that the geometry of tool wear, and the presence of built-up-edge, is strongly controlled by the chip curl. Evidence is also given which shows that some free-machining additives affect only the cutting temperature while others may affect the basic wear mechanism. Two simple theories are presented for calculating the rate of tool wear based on diffusion of tool material into the workpiece. While not conclusive, the results show remarkable agreement between predicted and measured wear based on a model wherein tool atoms jump into excess vacancies created in the chip by the plastic deformation of friction.

Cutting Forces and Tool Wear in Dry Milling of Ti6Al4V

2012 ◽  
Vol 565 ◽  
pp. 454-459 ◽  
Author(s):  
Yun Chen ◽  
Huai Zhong Li ◽  
Jun Wang
Keyword(s):  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Dry Milling ◽  
Workpiece Material ◽  
Tool Wear Mechanism ◽  
Coated Carbide ◽  
Carbide Inserts ◽  
Cutting Speeds

Titanium alloys are difficult-to-cut materials. This paper presents an experimental study of the effects of different cutting conditions and tool wear on cutting forces in dry milling Ti6Al4V with coated carbide inserts. The experimental results show that the peak forces increase with the increase in the feed rate and depth of cut. With the cutting speed increment in the range from 50 m/min to 150 m/min the peak forces decrease, while at further higher cutting speeds investigated peak forces increase. The decrease of the peak forces is due to thermal softening of the workpiece material and the increase is because of the strain hardening rate of Ti6Al4V. The tool wear experiment reveals that the major tool wear mechanism is the flank wear. The variations of the peak forces are caused by both the tool wear propagation and the thermal effects.

Experimental Study on Tool Wear in NC Dry Milling Resin Sand Mold Materials

2013 ◽  
Vol 395-396 ◽  
pp. 777-781
Author(s):  
Su Yu Wang ◽  
Lin Lin Ma ◽  
Wen Jie Yang
Keyword(s):  
Tool Wear ◽  
Wear Mechanism ◽  
High Speed ◽  
Tool Material ◽  
High Speed Steel ◽  
Cutting Parameters ◽  
Sand Mold ◽  
Mold Material ◽  
Tool Wear Mechanism ◽  
Coated Cemented Carbide

Experimental research was carried out to analyze the wear patterns of several tools which include high-speed steel (HSS), coated cemented carbide and ceramic tools, and to study the tool wear mechanism in milling resin sand mold materials. The main wear mechanism is abrasive wear and the dominant tool failure mode is flank wear. Different cutting parameters have different influence to the tool wear. In addition, it is essential to select suitable tool material with appropriate hardness. In this paper, the experiment results are contributive to choose proper cutting tool materials and parameters in milling resin sand mold material.

Laser Assisted Finish Turning of Inconel 718: Process Optimization

2009 ◽  
Author(s):  
Salar Tavakoli ◽  
Helmi Attia ◽  
Raul Vargas ◽  
Vincent Thomson
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Inconel 718 ◽  
Cutting Speed ◽  
Tool Material ◽  
Significant Drop ◽  
Nickel Based Superalloy ◽  
Wide Range ◽  
Coated Carbide ◽  
Conventional Machining

Generally, superalloys have superior strength and toughness compared to conventional engineering material. However, while applications for such materials are growing, the improvement of their machinability has not been improved in parallel. Of particular interest to the aerospace industry, are nickel-based superalloys. Inconel 718, which is one type of nickel-based superalloy, is considered difficult-to-machine at room temperature due to the fact that it retains much of its strength at high temperatures. Conventional machining methods applied to these materials results in excessive tool wear and poor surface finish. One approach, which is becoming increasingly popular with difficult-to-machine materials, is laser assisted machining (LAM). This study assesses the effect of LAM on the machinability of Inconel 718 using a triple-layer coated carbide tool in terms of cutting forces, tool wear and surface finish. A focused Nd:YAG laser beam was used as a localized heat source to thermally soften the workpiece prior to material removal. Finishing operations were assumed throughout the experiments. Cutting tests were performed over a wide range of cutting speeds (ranging from 100 to 500 m/min) and feeds (ranging from 0.125 to 0.500 mm/rev) to determine the optimum cutting speed and feed for each tool material. Results showed a significant drop in all three components of cutting force when thermal softening caused by the laser power was in effect. A two to three fold improvement was observed in terms of surface finish and tool wear under LAM conditions when compared to conventional machining.

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