The Performance of Diamond-Like Carbon Coated Drills in Thermally Assisted Drilling of Ti-6Al-4V

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
S. Bhowmick ◽  
A. T. Alpas
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Diamond Like Carbon ◽  
Carbon Coatings ◽  
Good Surface ◽  
Cooling Bath ◽  
Carbon Coated ◽  
Drilling Operations ◽  
Good Surface Finish ◽  
Rapid Tool

Drilling performances of diamond-like carbon coatings incorporating W (W-DLC) deposited on high-speed steel tools were evaluated when drilling Ti-6Al-4V at 25 °C and under thermally assisted machining (TAM) conditions at 400 °C. Dry drilling using W-DLC coated drills caused immediate tool failure as a result of titanium adhesion. The tool lives improved for TAM drilling using W-DLC when the Ti-6Al-4V was placed (with dry surface) in a cooling bath at −80 °C and resulted in low and uniform drilling torques as well as good surface finish. The low coefficient of friction (COF) of W-DLC against Ti-6Al-4V observed under TAM conditions was attributed to the formation of W oxide layers at the tool surface, as determined by Raman spectroscopy. Introducing a cooling bath was necessary in order to restrict the temperature rise in the workpiece that caused rapid tool wear above 500 °C during drilling operations and also to prevent adhesion with minimal built-up edge (BUE) formation during drilling. The TAM performance of W-DLC coated drills was shown to be similar to that of WC-Co drills used in conventional flooded drilling.

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.

Wear properties of diamond-like carbon coatings with silicon and chromium as adhesion layer using a high frequency reciprocating rig

2017 ◽  
Vol 231 (12) ◽  
pp. 1605-1615 ◽  
Author(s):  
Raman Maiti ◽  
Robin Mills
Keyword(s):  
Diamond Like Carbon ◽  
Wear Properties ◽  
Adhesion Layer ◽  
Stroke Length ◽  
Carbon Coatings ◽  
Wear Process ◽  
Coated Metal ◽  
Carbon Coated ◽  
Number Of Cycles ◽  
Cycles To Failure

The application of diamond-like carbon coatings to bearing surfaces is widespread from machining to bio-implants and has resulted in significant study of coating properties. The aim of this investigation was to determine the performance of two diamond-like carbon coatings, using chromium and silicon as adhesion layers. Linear reciprocating wear tests were carried out at room temperature using an AISI 440C steel ball reciprocating against the diamond-like carbon-coated metal substrate. The performance of the coatings under different contact pressures (500–3000 MPa); peak sliding velocities (28–378 mm/s); and stroke length, (1.5–4 mm). An electric resistance measurement was used to monitor coating failure owing to the dielectric nature of the tested coatings. An increase in contact pressure resulted in a decrease in number of cycles to failure for both the coatings. However, the number of cycles to failure increased proportionally with sliding speed. In addition, artifacts on the coating and blister formation generated coating debris which acted as a third body during the wear process. The debris caused complete delamination of the coatings initially at the ends of the wear scar. The silicon adhesion layer-coating samples were found to provide a greater resistance to failure due to it being thicker, harder, and more elastic as compared to samples having a chromium adhesion layer.

scholarly journals Analysis of the Performance of Drilling Operations for Improving Productivity

2021 ◽  
Author(s):  
Majid Tolouei-Rad ◽  
Muhammad Aamir
Keyword(s):  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Dimensional Accuracy ◽  
Vital Role ◽  
Machining Process ◽  
Drilling Process ◽  
Single Shot ◽  
Drilling Operations

Drilling is a vital machining process for many industries. Automotive and aerospace industries are among those industries which produce millions of holes where productivity, quality, and precision of drilled holes plays a vital role in their success. Therefore, a proper selection of machine tools and equipment, cutting tools and parameters is detrimental in achieving the required dimensional accuracy and surface roughness. This subsequently helps industries achieving success and improving the service life of their products. This chapter provides an introduction to the drilling process in manufacturing industries which helps improve the quality and productivity of drilling operations on metallic materials. It explains the advantages of using multi-spindle heads to improve the productivity and quality of drilled holes. An analysis of the holes produced by a multi-spindle head on aluminum alloys Al2024, Al6061, and Al5083 is presented in comparison to traditional single shot drilling. Also the effects of using uncoated carbide and high speed steel tools for producing high-quality holes in the formation of built-up edges and burrs are investigated and discussed.

Tool Wear of Diamond-Like Carbon-Coated High-Speed Steel with a Cr-Based Interlayer in Cutting of Aluminum Alloys

2012 ◽  
Vol 152-154 ◽  
pp. 74-79
Author(s):  
Tadahiro Wada ◽  
Koji Iwamoto ◽  
Hiroaki Sugita
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Tool Wear ◽  
High Speed ◽  
High Speed Steel ◽  
Diamond Like Carbon ◽  
Aluminum Alloy 6061 ◽  
Coated Tool ◽  
Alloy 6061

In cutting aluminum alloy 6061, continuous chips have a negative influence on the machining operation. Usually, Pb is added in order to break continuous chips. However, from the standpoint of environmental protection, it is necessary to improve chip breakability without adding Pb. One effective measure to improve chip breakability is by adding Si to aluminum alloy 6061. However, the influence of Si content on tool wear has not been fully examined. In this study, in order to clarify the influence of a diamond-like carbon (DLC) coating layer with a Cr-based interlayer, namely (Al,Cr)N, on cutting performance, aluminum alloys having different Si contents were turned. The substrate of the tool material was high-speed steel (1.4%C). The tool wear and the surface roughness were experimentally investigated. The following results were obtained: (1) In cutting two kinds of Al-Si alloys, namely the Al-2%Si alloy and Al-4%Si alloy, the progress of wear of the DLC/(Al,Cr)N-coated tool was slower than that of the DLC-coated tool. Therefore, the (Al,Cr)N interlayer was effective for decreasing the tool wear of the DLC-coated tool. (2) The wear progress of the two kinds of DLC-coated tools in cutting of Al-4%Si alloy was faster than that in cutting of Al-2%Si alloy. (3) In cutting of Al-2%Si alloy with the (Al,Cr)N/DLC-coated tool, the surface roughness was almost constant in the range of a cutting distance from 0.1 km to 9.5 km.

Effects of the duty factor on the surface characteristics of the plasma nitrided and diamond-like carbon coated high-speed steels

2000 ◽  
Vol 124 (2-3) ◽  
pp. 222-227 ◽  
Author(s):  
Goo-Hwan Jeong ◽  
Min-Sun Hwang ◽  
Bong-Yong Jeong ◽  
Myung-Ho Kim ◽  
Chongmu Lee
Keyword(s):  
High Speed ◽  
Surface Characteristics ◽  
Duty Factor ◽  
Diamond Like Carbon ◽  
Carbon Coated

scholarly journals Characteristics of Diamond-Like Carbon Coating Using Plasma Assisted Chemical Vapor Deposition on Steel Tool

2020 ◽  
Vol 3 (1) ◽  
pp. 27-32
Author(s):  
Saifudin Saifudin ◽  
Wawan Purwanto ◽  
Jerry Chih Tsong Su
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
High Speed ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Chemical Vapor ◽  
Physical And Mechanical Properties ◽  
Diamond Like Carbon ◽  
Dlc Coating ◽  
Wear And Corrosion

High Speed Steel (HSS) tool is commonly used in engineering applications, especially as cutters. The shortfall of this materials are wear and corrosion. However, these can be reduced by coating the surface of the material. Therefore, the purpose of this research is to investigate the effects of Diamond Like Carbon (DLC) coating, quenching heating treatment, and tempering on the physical and mechanical properties of HSS surface. The physical characteristics which will be investigated is the micro structure,  while the mechanical characteristics are hardness, wear and corrosion rate. HSS has variations in their chemical composition (% mass): 0.75–1.5 C,  Co >12, V > 5, 4–4.5 Cr,10–20 W and Mo. Furthermore, DLC coating uses Plasma Assisted Chemical Vapor Deposition (PACVD) technique with variation in the duration of coating (1,2,3,4,5 and 6 hours) at temperature of 300℃, with pressure variations of 1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 millibar. DLC coating material be treated from methane or ethane gas, which is streamed into the fire with Argon (Ar). The result shows variations in DLC coating and the hardness grade depends on the coating time and pressure variation. DLC coating for a duration of 4 hours under 1.8 mbar pressure can reduce the surface hardness of HSS tool by 62% accompanied by increased ductility.

A New Experimental Approach to Determination of Critical Depth in High Speed Machining of Soda-Lime Glass

2012 ◽  
Vol 576 ◽  
pp. 23-27
Author(s):  
M.A. Mahmud ◽  
A.K.M. Nurul Amin ◽  
M.D. Arif
Keyword(s):  
High Speed ◽  
End Milling ◽  
Soda Lime ◽  
Depth Of Cut ◽  
Soda Lime Glass ◽  
Critical Depth ◽  
Good Surface ◽  
Transition Depth ◽  
Good Surface Finish

Soda-Lime glass is a very hard and brittle material which is commonly used as window panels and many other common applications. Due to its low fracture toughness it is very difficult to machine and obtain good surface finish under nornal cutting conditions. Hence, machining has to be done in ways to avoid brittle fracture on the finished machined surface. Such machining is only possible under ductile mode machining conditions when the removal of material is performed in the plastic state. However, ductile mode machining requires that during machining the temperature generated in the cutting zone in the working temperature range of glass to avoid crack formation during machining. This makes all types of machining of glass an extremely challenging affair, given the current state and mode of mechanical machining. This research paper elucidates the results of an experimental study for determination of critical depth of cut as a function of cutting parameters in high speed end milling of soda-lime glass. The critical depth is defined as the depth of cut at which crack formation the material is initiated for a given high speed attachment. In determining the critical depth as well as the ductile brittle transition depth, machining was performed on a tapered surface. Vibration signals from an accelerometer in time domain (amplitude vs. time display) and the surface characteristics were used in identifying the critical depth of cut. The new method has been found to be useful in online determination of the critical depth, as well as the brittle-ductile transition depth, for generating crack-free surfaces with good surface finish in high speed end milling of soda lime glass.

scholarly journals Enhancement of sp3 C Fraction in Diamond-like Carbon Coatings by Cryogenic Treatment

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Jihua Peng ◽  
Jingwen Liao ◽  
Yinglong Peng ◽  
Yang Xiao ◽  
Jinhai Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Photoelectron Spectroscopy ◽  
High Speed ◽  
Cryogenic Treatment ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Diamond Like Carbon ◽  
Dlc Coatings ◽  
Bonding Structure

Diamond-like carbon (DLC) coatings deposited onto high-speed-steel surfaces were subjected to deep cryogenic treatment (DCT) at temperatures of −120 to −196 °C to investigate the evolution of microstructure, bonding structure, and mechanical properties. The surface morphology and the bonding structure of the DLC coatings were studied using scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy. It is found that DCT affects the surface morphology, especially the size and the height of the aggregates. For those DLCs with more than 50% sp3 C fraction, the sp2 C → sp3 C transformation occurred in coatings treated at a temperature of −120 to −160 °C; and the maximum fraction of sp3 C was obtained after treatment at −140 °C. Almost keeping the wear resistance of DLCs, DCT can improve the adhesion strength, and surface hardness. The findings of this study indicate that DCT will be a potential post-treatment method to tune the microstructure and mechanical performance of DLC coatings.

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