Effects of Co, Ti Interlayer, and Post-Annealing on the Adhesion Property between TiN Coatings and WC-Co Substrate

2006 ◽  
Vol 118 ◽  
pp. 281-286 ◽  
Author(s):  
Dong Shik Kang ◽  
Jung Tae Ok ◽  
Su Jeong Heo ◽  
Eun Young Choi ◽  
Myung Chang Kang ◽  
...  

In order to improve adhesion strength between TiN coatings and WC-Co substrate, two kinds of interlayer of Co and Ti were pre-deposited before TiN coating process. Thickness and postannealing effects of each interlayer on the adhesion property were investigated through scratch test in this work. Introduction of thin Ti interlayer largely enhanced the adhesion strength between TiN coatings and WC-Co substrate in scratch test. The critical load, Lc2 increased from 64 N without Ti interlayer up to 130N with Ti one of ~ 0.15 thickness. However, post-annealing of TiN/Ti/WCCo system at high temperature of 600 reduced the critical load again. The Ti interlayer caused a deficit of Co content in WC-Co substrate during annealing through diffusion of Co element into Ti interlayer. The reduction of critical load after post-annealing was believed due to diminution in mechanical properties of the substrate derived from the Co deficit in WC-Co substrate. On the other hand, introduction of thin Co interlayer of ~ 0.027 thickness also increased the critical load up to 84 N and improved failure mode, but did not reduce the critical load even after annealing, rather increased it. And, any Co deficit of the substrate was not found after annealing for TiN/Co/WC-Co system.

2013 ◽  
Vol 750 ◽  
pp. 138-141
Author(s):  
Liang Hao ◽  
Yun Lu ◽  
Hiromasa Sato ◽  
Hiroshi Asanuma ◽  
Fu Sheng Pan

The influence of intermittent air introduction on the formation of Zn films during mechanical coating process was investigated. A series of contrast experiments were carried out. The XRD and EDS results showed that Zn particles were slightly oxidized. The SEM images indicated that disk-like zinc oxide (ZnO) nanocrystals were formed. The formation of disk-like ZnO made the morphology of Zn films more uneven and irregular. On the other hand, it increased the adhesion strength of Zn films to Al2O3 balls and hence the exfoliation of Zn films was not found.


2008 ◽  
Vol 569 ◽  
pp. 165-168 ◽  
Author(s):  
Chan Joo Lee ◽  
Jung Min Lee ◽  
Byung Min Kim

The deposition of thin hard coating onto tool steel is done to improve the surface properties such as wear, corrosion. The adhesion strength between substrate and coating is one of important parameters in practical applications since coating failure affects the lifetime of tool directly. Scratch test with acoustic emission(AE) technique was performed to evaluate the adhesion strength qualitative by observing the friction load vs. the normal load curves, the acoustic emission signal generated by the damage of coatings and the scratch track using an optical microscope. In this study, the effect of substrate hardness on the adhesion strength was investigated by evaluating critical load and work of adhesion and observing AE signal and failure mode in scratch track using optical microscope. Coatings were individually deposited on six substrates by means of physical or chemical vapor deposition(PVD, CVD) process and TD process. The critical load of the substrates with nitride layer is higher than without nitride. Although high load causes higher stresses which make flaking occur in the coating-substrate interface, the work of adhesion of harder substrates is also high. Because harder substrates have small contact area causing lower the plastic deformation around stylus.


2018 ◽  
Vol 25 (03) ◽  
pp. 1830004 ◽  
Author(s):  
HOSSEIN SHARIFI ◽  
MAHMOOD ALIOFKHAZRAEI ◽  
GHASEM BRATAI DARBAND ◽  
SUMAN SHRESTHA

Adhesion strength is one of the important properties that reflects the quality of a plasma electrolytic oxidation (PEO) coating. Scratch testing can be considered as an appropriate technique to evaluate the adhesion strength of PEO coatings on magnesium, titanium, and aluminum substrates. The scratch test is usually performed either under a constant or a progressively increasing normal load, where the critical load is used as a measure of adhesion strength of the coatings. In this review paper, the effect of different factors such as duration of coating processing, electrolyte composition, and processing current density, as well as different additives to the electrolyte bath, was studied on the adhesion strength of PEO coatings formed on magnesium, titanium, and aluminum substrates. It is understood that an optimum increase in process time and input energy leads to a corresponding increase in thickness of the PEO dense oxide layer and, consequently, an increase in critical load and adhesion strength. Moreover, the electrolyte composition and additives were found to affect the coating microstructure and composition and, subsequently, the coating adhesion strength.


2009 ◽  
Vol 16 (01) ◽  
pp. 29-35 ◽  
Author(s):  
MUBARAK ALI ◽  
ESAH HAMZAH ◽  
NOUMAN ALI

Titanium nitride ( TiN ) widely used as hard coating material was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The goal of this study was to examine the effect of ion etching with and without titanium ( Ti ) and chromium ( Cr ) on the adhesion strength of TiN coatings deposited on tool steels. From the scratch tester, it was observed that by increasing Ti ion etching showed an increase in adhesion strength of the deposited coatings. The coatings deposited with Cr ion etching showed poor adhesion compared with the coatings deposited with Ti ion etching. Scratch test measurements showed that the coating deposited with titanium ion etching for 16 min is the most stable coating and maintained even at the critical load of 66 N. The curve obtained via penetration depth along the scratch trace is linear in the case of HSS, whereas is slightly flexible in the case of D2 tool steel. The coatings deposited on HSS exhibit better adhesion compared with those on D2 tool steel.


Author(s):  
Dong Shik Kang ◽  
Jung Tae Ok ◽  
Su Jeong Heo ◽  
Eun Young Choi ◽  
Myung Chang Kang ◽  
...  

2013 ◽  
Vol 562-565 ◽  
pp. 96-101
Author(s):  
Xiao Lei Zhang ◽  
Li Qun Du ◽  
Ao An Wang

During the fabrication process of metal microdevice by SU-8 UV-LIGA technology, due to the poor adhesion strength between SU-8 photoresist and metal substrate it is common for interface separated and bind failure. In this paper pull-off test, scratch test and indentation test were performed to evaluate the adhesion property between SU-8 photoresist and metal substrate, and the feasibility of these three methods was compared. The result shows that the pull-off test fails to evaluate real interface adhesion strength because of the great possibilities of mixed debond appearance which makes the experimental data discrete and inaccurate. The scratch test and the indentation test can efficiently and accurately evaluate the interface adhesion strength between SU-8 photoresist and metal substrate and are demonstrated two preferable methods.


2003 ◽  
Vol 766 ◽  
Author(s):  
A. Sekiguchi ◽  
J. Koike ◽  
K. Ueoka ◽  
J. Ye ◽  
H. Okamura ◽  
...  

AbstractAdhesion strength in sputter-deposited Cu thin films on various types of barrier layers was investigated by scratch test. The barrier layers were Ta1-xNx with varied nitrogen concentration of 0, 0.2, 0.3, and 0.5. Microstructure observation by TEM indicated that each layer consists of mixed phases of β;-Ta, bcc-TaN0.1, hexagonal-TaN, and fcc-TaN, depending on the nitrogen concentration. A sulfur- containing amorphous phase was also present discontinuously at the Cu/barrier interfaces in all samples. Scratch test showed that delamination occurred at the Cu/barrier interface and that the overall adhesion strength increased with increasing the nitrogen concentration. A good correlation was found between the measured adhesion strength and the composing phases in the barrier layer.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ruud P. van Hove ◽  
Inger N. Sierevelt ◽  
Barend J. van Royen ◽  
Peter A. Nolte

Surfaces of medical implants can be enhanced with the favorable properties of titanium-nitride (TiN). In a review of English medical literature, the effects of TiN-coating on orthopaedic implant material in preclinical studies were identified and the influence of these effects on the clinical outcome of TiN-coated orthopaedic implants was explored. The TiN-coating has a positive effect on the biocompatibility and tribological properties of implant surfaces; however, there are several reports of third body wear due to delamination, increased ultrahigh molecular weight polyethylene wear, and cohesive failure of the TiN-coating. This might be due to the coating process. The TiN-coating process should be optimized and standardized for titanium alloy articulating surfaces. The clinical benefit of TiN-coating of CoCrMo knee implant surfaces should be further investigated.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Mohamed Ali Hassan ◽  
Hossam M. Yehia ◽  
Ahmed S. A. Mohamed ◽  
Ahmed Essa El-Nikhaily ◽  
Omayma A. Elkady

To improve the AlCoCrFeNi high entropy alloys’ (HEAs’) toughness, it was coated with different amounts of Cu then fabricated by the powder metallurgy technique. Mechanical alloying of equiatomic AlCoCrFeNi HEAs for 25 h preceded the coating process. The established powder samples were sintered at different temperatures in a vacuum furnace. The HEAs samples sintered at 950˚C exhibit the highest relative density. The AlCoCrFeNi HEAs model sample was not successfully produced by the applied method due to the low melting point of aluminum. The Al element’s problem disappeared due to encapsulating it with a copper layer during the coating process. Because the atomic radius of the copper metal (0.1278 nm) is less than the atomic radius of the aluminum metal (0.1431 nm) and nearly equal to the rest of the other elements (Co, Cr, Fe, and Ni), the crystal size powder and fabricated samples decreased by increasing the content of the Cu wt%. On the other hand, the lattice strain increased. The microstructure revealed that the complete diffusion between the different elements to form high entropy alloy material was not achieved. A dramatic decrease in the produced samples’ hardness was observed where it decreased from 403 HV at 5 wt% Cu to 191 HV at 20 wt% Cu. On the contrary, the compressive strength increased from 400.034 MPa at 5 wt% Cu to 599.527 MPa at 15 wt% Cu with a 49.86% increment. This increment in the compressive strength may be due to precipitating the copper metal on the particles’ surface in the nano-size, reducing the dislocations’ motion, increasing the stiffness of produced materials. The formability and toughness of the fabricated materials improved by increasing the copper’s content. The thermal expansion has increased gradually by increasing the Cu wt%.


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