Adhesion improvement of diamond coatings on cemented carbide with high cobalt content using PVD interlayer

2013 ◽  
Vol 34 ◽  
pp. 70-75 ◽  
Author(s):  
F. Xu ◽  
J.H. Xu ◽  
M.F. Yuen ◽  
L. Zheng ◽  
W.Z. Lu ◽  
...  
Keyword(s):  
Cobalt Content ◽  
Cemented Carbide ◽  
Diamond Coatings

scholarly journals Multilayer Diamond Coatings Applied to Micro-End-Milling of Cemented Carbide

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3333
Author(s):  
Eduardo L. Silva ◽  
Sérgio Pratas ◽  
Miguel A. Neto ◽  
Cristina M. Fernandes ◽  
Daniel Figueiredo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
End Milling ◽  
Interfacial Stress ◽  
Cemented Carbide ◽  
Air Cooling ◽  
Micro Machining ◽  
Diamond Coatings ◽  
Wear Properties ◽  
High Adhesion ◽  
Micro End Milling

Cobalt-cemented carbide micro-end mills were coated with diamond grown by chemical vapor deposition (CVD), with the purpose of micro-machining cemented carbides. The diamond coatings were designed with a multilayer architecture, alternating between sub-microcrystalline and nanocrystalline diamond layers. The structure of the coatings was studied by transmission electron microscopy. High adhesion to the chemically pre-treated WC-7Co tool substrates was observed by Rockwell C indentation, with the diamond coatings withstanding a critical load of 1250 N. The coated tools were tested for micro-end-milling of WC-15Co under air-cooling conditions, being able to cut more than 6500 m over a period of 120 min, after which a flank wear of 47.8 μm was attained. The machining performance and wear behavior of the micro-cutters was studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Crystallographic analysis through cross-sectional selected area electron diffraction patterns, along with characterization in dark-field and HRTEM modes, provided a possible correlation between interfacial stress relaxation and wear properties of the coatings. Overall, this work demonstrates that high adhesion of diamond coatings can be achieved by proper combination of chemical attack and coating architecture. By preventing catastrophic delamination, multilayer CVD diamond coatings are central towards the enhancement of the wear properties and mechanical robustness of carbide tools used for micro-machining of ultra-hard materials.

Effects of CH4 Concentration on CVD Diamond Coatings Deposited on Cemented Carbide Cutting Cools

2006 ◽  
Vol 532-533 ◽  
pp. 480-483 ◽  
Author(s):  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Min Wang ◽  
Feng Xu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Great Influence ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cemented Carbide ◽  
Diamond Coatings ◽  
Ch4 Concentration

Chemical vapor deposition (CVD) diamond coatings were deposited on cemented carbide cutting cools by an electron-assisted hot filament chemical vapor deposition (EACVD) equipment developed by the authors. The CVD diamond coatings were studied by Scanning Electron Microscope (SEM) and Raman Scattering Spectroscopy (Raman). The experimental results show that CH4 concentration in the source gas performs great influence on the micro-structure, surface roughness, composition, residual stress and adhesion of the CVD diamond coatings. The increase of CH4 concentration results the change of diamond crystal from {111} orientation to {100} orientation, the decrease of the surface roughness and the increase of sp2 carbon in the CVD diamond coatings. A residual compressive stress exists in the CVD diamond coatings. The residual stress decreases with increasing CH4 concentration. A higher or lower CH4 concentration tends to reduce adhesion stress of the continuous CVD diamond coatings.

Effect of a two-step pretreatment method on adhesion of CVD diamond coatings on cemented carbide substrates

2004 ◽  
Vol 187 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Jinqi Miao ◽  
Jianhua Song ◽  
Yundong Xue ◽  
Yumei Tong ◽  
Weizhong Tang ◽  
...  
Keyword(s):  
Cvd Diamond ◽  
Cemented Carbide ◽  
Diamond Coatings ◽  
Pretreatment Method

The Effect of Grain Size and Cobalt Content on the Wear of Ultrafine Cemented Carbide Tools

2014 ◽  
Vol 875-877 ◽  
pp. 1344-1351
Author(s):  
Jian Bing Cheng ◽  
Si Qin Pang ◽  
Xi Bin Wang ◽  
Xi Bin Wang ◽  
Chen Guang Lin
Keyword(s):  
Grain Size ◽  
Tool Wear ◽  
Tool Life ◽  
Wear Mechanism ◽  
Wear Mechanisms ◽  
High Strength Steels ◽  
Cobalt Content ◽  
Cemented Carbide ◽  
Cemented Carbide Tools ◽  
Cutting Speeds

This work contributes to a better understanding of wear mechanisms of ultrafine cemented carbide cutting tools used in turning operation of superalloy and high strength steels at high cutting speeds. The main objective of this work is to verify the influence of grain size and the cobalt content of ultrafine cemented carbide tools on tool life and tool wear mechanism. The main conclusions are that grain size and the cobalt content of ultrafine cemented carbide tools strongly influence tool life and tool wear involve different mechanisms. The wear mechanisms of different grain size and the cobalt content of ultrafine cemented carbide tools observed on the rake face at these conditions were adhesion and notch, at the end of tool life, adhesion was the main wear mechanism at higher cutting speeds.

Influences of Cobalt Content on the Physical and Tribological Properties of Cemented Tungsten Carbide Used in Sheet Metal Forming Application

2014 ◽  
Vol 966-967 ◽  
pp. 80-86
Author(s):  
Varunee Premanond ◽  
Onnjira Diewwanit
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Friction Coefficient ◽  
Tungsten Carbide ◽  
Cobalt Content ◽  
Steel Ball ◽  
Cemented Carbide ◽  
Average Grain Size ◽  
Stainless Steel Ball ◽  
Cemented Tungsten Carbide

The objective of this work is to investigate the tribological behavior between WC-Co cemented carbide and austenitic stainless steel under repeated rotation sliding. Influences of cobalt content of commercial grade cemented tungsten carbide on friction coefficient and material transfer phenomena have been explored. Three grades of commercial WC-Co cemented carbide with similar medium WC grain size were employed; WC-12Co, WC-14Co and WC-19Co. The average grain size were ranges between 0.85-1.1 μm and the hardness of about 86-88 HRA have been given by the material maker. The composition analysis and the average grain size of tungsten carbide have been rechecked. Furthermore, the carbide grain size distribution was recorded and the fracture toughness was calculated for each WC-Co grade. The experiments were carried out using ball on disk test. The ball was made from SUS304 grade and the disk was fabricated by 3 grades of WC-Co cemented carbide. The friction coefficient was measured under dry sliding. The characteristics of contact surfaces were explored on the ball as well as on the disk after tests to reveal the presence of a metallic transfer on the WC-Co cemented carbide disk and the wear scar on the ball. The measurement results of wear volume on the stainless steel ball disclosed that maximum wear rate was found from the stainless steel ball rub against WC-19Co tool material.

ON THE USE OF Mo/Mo2C GRADIENT INTERLAYERS IN DIAMOND DEPOSITION ONTO CEMENTED CARBIDE SUBSTRATES

2016 ◽  
Vol 23 (02) ◽  
pp. 1550109 ◽  
Author(s):  
JIE GAO ◽  
HONGJUN HEI ◽  
KE ZHENG ◽  
XUEYAN GAO ◽  
XIAOPING LIU ◽  
...  
Keyword(s):  
Diffusion Layer ◽  
Cemented Carbide ◽  
Binder Phase ◽  
Diamond Coatings ◽  
Diamond Deposition ◽  
Depth Direction ◽  
Gradient Diffusion ◽  
Glow Plasma ◽  
Excellent Adhesion ◽  
Plasma Surface Alloying

Molybdenum/molybdenum carbide (Mo/Mo2C) gradient interlayers were prepared via double glow plasma surface alloying (DGPSA) technique onto cemented carbide (WC–Co) substrates for diamond deposition. The morphologies, phase composition and adhesion of the interlayers were investigated, as well as their effect on the subsequent diamond deposition. The results indicated that the Mo/Mo2C gradient interlayer deposited on WC–Co substrate was composed of 4.0-[Formula: see text]m-thick diffusion layer and 2.7-[Formula: see text]m-thick deposition layer. The Mo concentration decreased gradually with the depth direction whereas the Co and W concentrations increased. As a result, the Co binder phase was completely restricted within the substrate by the diffusion layer. The presence of gradient diffusion layer ensured excellent adhesion of the interlayer. Subsequently, nanocrystalline diamond coatings with excellent adhesion were deposited on the interlayered substrates. Thus, the Mo/Mo2C gradient interlayers deposited via DGPSA technique were demonstrated as a novel option for depositing adherent diamond coatings on WC–Co substrates.

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