Machining Response and Damage Evolution of Amorphous Carbon Coated Tools in High-Speed Micromilling of Ti–6Al–4V

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Rinku K. Mittal ◽  
Salil S. Kulkarni ◽  
Harish Barshilia ◽  
Ramesh Singh
Keyword(s):  
Amorphous Carbon ◽  
Cutting Forces ◽  
Damage Evolution ◽  
Damage Assessment ◽  
High Speed ◽  
Solid Lubricant ◽  
Coated Tools ◽  
Tool Coating ◽  
Carbon Coated ◽  
Cutting Zone

Abstract Micromilling process is widely used to create complex 3D miniature products due to its flexibility and its ability to process difficult-to-cut material like Titanium alloys. High rotational speeds are used to overcome the limited flexural stiffness of the tool but the cutting zone temperatures rise due to the high rotational speeds. In addition to this, friction between the tool workpiece and tool chip also plays a major role in the temperature rise. The friction and temperature affect the cutting forces, tool life and stability of the process. To reduce the friction and heat generation, nanostructured solid lubricant coatings can be used. This study is focused on characterizing the effect of amorphous carbon (WC/a-C) coating on the micromachining response during high-speed micromilling of Ti–6Al–4V. A decrease in cutting forces for coated tools is observed for lower feed. A comprehensive tool coating damage assessment has been done in terms of debonding area on flank and rake faces. An increase in debonding area has been observed with lengths of cut but at a feed/flute of 4 μm, tool breakage occurs after a machining length of 60 mm.

Granulation of Extruded Plastic Wires: Influence of Tool Coating Properties and Tool Geometry on Cutting Forces and Tool Wear

2016 ◽  
Vol 1140 ◽  
pp. 181-188
Author(s):  
Macario Cardone ◽  
Matthias Putz ◽  
Gerhard Schmidt ◽  
Martin Dix ◽  
Jürgen Friedrich ◽  
...  
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Polyamide 6 ◽  
Machining Process ◽  
Test Facility ◽  
Tool Geometry ◽  
Coated Tools ◽  
Tool Coating ◽  
Before And After ◽  
Wear Evaluation

Granulators are widely used to reduce reinforced and unreinforced plastic strands in small pieces. The tools implemented in this machining process are mainly made of high-speed steel. This work investigates diverse PVD hard thin coatings with the aim of improving tool life and efficiency in granulation technology. A test facility reproducing the main features of a real granulator has been designed and assembled. The machined strand materials are ABS plastic and fibreglass-reinforced polyamide 6, while the tested PVD films are CrN, TiCN, TiAlN and two different diamond-like carbon coatings. The wear evaluation of all coated tools has been done via structured light projection, together with a scanning electron microscopy-based analysis, before and after their implementation on the test facility. Furthermore, a suitable 2D finite element modelling of the machining process has been realized.

Performance Profiling of Nanoparticulate Graphite Powder as Lubricant in the Machining of AISI 1040 Steel under Variable Machining Conditions

2014 ◽  
Vol 984-985 ◽  
pp. 15-24 ◽  
Author(s):  
S. Srikiran ◽  
K. Ramji ◽  
B. Satyanarayana
Keyword(s):  
Particle Size ◽  
Surface Finish ◽  
Cutting Forces ◽  
Solid Lubricant ◽  
Graphite Powder ◽  
Nano Particles ◽  
Chemical Degradation ◽  
Work Piece ◽  
Tool Temperature ◽  
Cutting Zone

The generation of heat during machining at the cutting zone adversely affects the surface finish and tool life. The heat at the cutting zone, which plays a negative role due to poor thermal conductivity, resistance to wear, high strength at high temperatures and chemical degradation can be overcome by the use of proper lubrication. Advancements in the field of tribology have led to the use of solid lubricants replacing the conventional flood coolants. This work involves the use of nanoparticulate graphite powder as a lubricant in turning operations whose performance is judged in terms of cutting forces, tool temperature and surface finish of the work piece. The experimentation revealed the increase in cutting forces and the tool temperature when the solid lubricant used is decreased in particle size. The surface finish deteriorated with the decrease in particle size of the lubricant in the nanoregime.Keywords-Turning, Solid lubricant, Graphite, Minimum Quantity Lubrication, nano–particles,Weight percentage,Frictioncoefficient.

Research on Cutting Performance of Graphite-Like Carbon Coated Tools in Dry Drilling of Ferrous Metal

2010 ◽  
Vol 455 ◽  
pp. 467-471
Author(s):  
Ji Ming Xiao ◽  
Yan Li ◽  
L.J. Bai ◽  
Qi Long Yuan ◽  
Jian Ming Zheng
Keyword(s):  
High Speed ◽  
Ferrous Metal ◽  
High Speed Steel ◽  
High Hardness ◽  
Cutting Performance ◽  
Low Friction ◽  
Dry Cutting ◽  
Coated Tools ◽  
Carbon Coated ◽  
Twist Drills

The graphite-like carbon (GLC) coating was deposited onto high-speed steel (HSS) twist drills by magnetron sputter ion plating technique. The drilling tests were performed on the ferrous metal under dry cutting conditions. By the analysis and comparison of the flank wear and the drilling forces on drills, the cutting performance of GLC coated HSS tools was researched. The results show that GLC coating with high hardness and low friction coefficient, due to its good adhesion and match with HSS substrate, can significantly improve the cutting performance of HSS twist drills, prolong the tool life, decrease the drilling forces in drilling the ferrous metal. And its cutting performance is better than the hard coated drills in the lower speed, but its thermal stability is inferior to the hard coated drills in the higher speed.

The Simulation of Cutting Force and Temperature in High-Speed Milling of Ti-6Al-4V

2010 ◽  
Vol 139-141 ◽  
pp. 768-771
Author(s):  
Zhen Chao Yang ◽  
Ding Hua Zhang ◽  
Xin Chun Huang ◽  
Chang Feng Yao ◽  
Jun Xue Ren
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Temperature ◽  
General Purpose ◽  
Milling Process ◽  
Maximum Temperature ◽  
High Speed Milling ◽  
Milling Parameters ◽  
Cutting Zone

In order to provide theory basis for optimizing high-speed milling parameters, the high-speed milling process of titanium alloy Ti-6Al-4V was modeled using the commercial general purpose machining software package ADVANTEDGE. Effects of milling parameters like milling speed, feed per tooth, milling depth and milling width on cutting force and temperature were analyzed. The results show that cutting forces decrease with milling speed increasing, and increase with feed per tooth, milling depth and milling width, and the influences of feed per tooth, milling depth and milling width on cutting forces are significant. The maximum temperature in the cutting zone located on the rake face at a distance of about 0.02~0.03 mm from the tool tip. As milling speed and feed per tooth increase, the maximum temperature in the cutting area increases. The milling speed has significant impact on cutting temperature, but the milling depth has little impact.

scholarly journals Cutting forces and wear analysis of Si3N4 diamond coated tools in high speed machining

Vacuum ◽  
2008 ◽  
Vol 82 (12) ◽  
pp. 1415-1420 ◽  
Author(s):  
R.P. Martinho ◽  
F.J.G. Silva ◽  
A.P.M. Baptista
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
High Speed Machining ◽  
Coated Tools ◽  
Wear Analysis

Study on mechanical properties and damage evolution of carbonaceous shale under triaxial compression with acoustic emission

2021 ◽  
pp. 105678952199119
Author(s):  
Kai Yang ◽  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Fei Wan
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Water Content ◽  
Damage Evolution ◽  
Damage Assessment ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Damage Variable ◽  
Natural State ◽  
Carbonaceous Shale

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.

scholarly journals Evaluation of Cutting-Tool Coating on the Surface Roughness and Hole Dimensional Tolerances during Drilling of Al6061-T651 Alloy

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1783
Author(s):  
Hamza A. Al-Tameemi ◽  
Thamir Al-Dulaimi ◽  
Michael Oluwatobiloba Awe ◽  
Shubham Sharma ◽  
Danil Yurievich Pimenov ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Cutting Tool ◽  
Good Practice ◽  
Cutting Tools ◽  
Statistical Design ◽  
Cutting Parameters ◽  
Statistical Design Of Experiments ◽  
Hole Quality ◽  
Coated Tools ◽  
Tool Coating

Aluminum alloys are soft and have low melting temperatures; therefore, machining them often results in cut material fusing to the cutting tool due to heat and friction, and thus lowering the hole quality. A good practice is to use coated cutting tools to overcome such issues and maintain good hole quality. Therefore, the current study investigates the effect of cutting parameters (spindle speed and feed rate) and three types of cutting-tool coating (TiN/TiAlN, TiAlN, and TiN) on the surface finish, form, and dimensional tolerances of holes drilled in Al6061-T651 alloy. The study employed statistical design of experiments and ANOVA (analysis of variance) to evaluate the contribution of each of the input parameters on the measured hole-quality outputs (surface-roughness metrics Ra and Rz, hole size, circularity, perpendicularity, and cylindricity). The highest surface roughness occurred when using TiN-coated tools. All holes in this study were oversized regardless of the tool coating or cutting parameters used. TiN tools, which have a lower coating hardness, gave lower hole circularity at the entry and higher cylindricity, while TiN/TiAlN and TiAlN seemed to be more effective in reducing hole particularity when drilling at higher spindle speeds. Finally, optical microscopes revealed that a built-up edge and adhesions were most likely to form on TiN-coated tools due to TiN’s chemical affinity and low oxidation temperature compared to the TiN/TiAlN and TiAlN coatings.

Cutting Temperature and Cutting Forces Investigation Based on the Taguchi Design Method when High-Speed Milling of Titanium Matrix Composites with PCD Tool

2016 ◽  
Vol 836-837 ◽  
pp. 168-174 ◽  
Author(s):  
Ying Fei Ge ◽  
Hai Xiang Huan ◽  
Jiu Hua Xu
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Volume Fraction ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth

High-speed milling tests were performed on vol. (5%-8%) TiCp/TC4 composite in the speed range of 50-250 m/min using PCD tools to nvestigate the cutting temperature and the cutting forces. The results showed that radial depth of cut and cutting speed were the two significant influences that affected the cutting forces based on the Taguchi prediction. Increasing radial depth of cut and feed rate will increase the cutting force while increasing cutting speed will decrease the cutting force. Cutting force increased less than 5% when the reinforcement volume fraction in the composites increased from 0% to 8%. Radial depth of cut was the only significant influence factor on the cutting temperature. Cutting temperature increased with the increasing radial depth of cut, feed rate or cutting speed. The cutting temperature for the titanium composites was 40-90 °C higher than that for the TC4 matrix. However, the cutting temperature decreased by 4% when the reinforcement's volume fraction increased from 5% to 8%.

Predicting the High Speed Cutting Process of Titanium Alloy by Finite Element Method

2011 ◽  
Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Cutting Process ◽  
Fe Model ◽  
Dry Cutting ◽  
Friction Coefficients ◽  
Machining Conditions

To predict the cutting forces and cutting temperatures accurately in high speed dry cutting Ti-6Al-4V alloy, a Finite Element (FE) model is established based on ABAQUS. The tool-chip-work friction coefficients are calculated analytically using the measured cutting forces and chip morphology parameter obtained by conducting the orthogonal (2-D) machining tests. It reveals that the friction coefficients between tool-work are 3∼7 times larger than that between tool-chip, and the friction coefficients of tool-chip-work vary with feed rates. The analysis provides a better reference for the tool-work-chip friction coefficients than that given by literature empirically regardless of machining conditions. The FE model is capable of effectively simulating the high speed dry cutting process of Ti-6Al-4V alloy based on the modified Johnson-Cook model and tool-work-chip friction coefficients obtained analytically. The FE model is further validated in terms of predicted forces and the chip morphology. The predicted cutting force, thrust force and resultant force by the FE model agree well with the experimentally measured forces. The errors in terms of the predicted average value of chip pitch and the distance between chip valley and chip peak are smaller. The FE model further predicts the cutting temperature and residual stresses during high speed dry cutting of Ti-6Al-4V alloy. The maximum tool temperatures exist along the round tool edge, and the residual stress profiles along the machined surface are hook-shaped regardless of machining conditions.

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