• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.585-589
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• 2012

The characteristics of interface layer and the effect of mole fraction of inlet gas mixture($B_2H_6/H_2/N_2/TiCl_4$) on the microstructure of Ti(B,N) films were studied by microwave plasma hot filament CVD process. Ti(B,N) films were deposited on a substrate(STD-61) to develop a high performance of resistance wear coating tool. Ti(B,N) films were obtained at a gas pressure of 1 torr, bias voltage of 300 V and substrate temperature of $480^{\circ}C$ in $B_2H_6/H_2/N_2/TiCl_4$gas system. It was found that TiN, $TiB_2$, TiB and hexagonal boron nitride(h-BN) phases exist in thin layer on the STD-61.

• Korean Journal of Materials Research
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• v.1 no.1
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• pp.9-17
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• 1991

TiC coating formed on $Si_3N_4-TiC$ composite ceramic by chemical vapor deposition (CVD) has an improved microstructures, better thermal shock resistance and interfacial bonding than TiN coating does. TiN coating formed by CVD, however, has lower friction coefficients against steels and better chemical stability. The experimental results indicate that the coated insert is superior to the uncoated one in flank and crater wear resistance. And the multilayer coating shows an improved wear resistance than the monolayer coating.

• Journal of the Korean institute of surface engineering
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• v.37 no.3
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• pp.137-145
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• 2004

This study surveys the microscopic wear of CVD TiN coatings in repeated sliding, using the SEM Tribosystem as in-situ system. According to the research, the depth of wear groove and the specific wear amount are changed by the transition of the microscopic wear mode. This investigation leads to the fact that the change of wear characteristics produces the transition of the wear mode. In this survey, four modes are observed for CVD TiN coatings with the thickness of 1.6$\mu\textrm{m}$: ploughing, powder formation, flake formation and coating delimitation. The microscopic wear properties is quantitatively evaluated in terms with the microscopic wear mode and the specific wear amount. These relationships prove that the observation of wear modes with a SEM Tribosystem is useful to evaluate wear properties.

• Tribology and Lubricants
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• v.4 no.2
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• pp.44-51
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• 1988

Titanium carbide(TiC), Titanium nitride(TiN), and Titanium carbonnitride(Ti(C,N)) films were deposited on $Si_3N_4$-TiC composite cutting tools by chemical vapor deposition(CVD) using $TiCl_4-CH_4-H_2$, $TiCl_4-N_2-H_2$, and $TiCl_4-CH_4-N_2-H_2$ gas mixtures, respectively. The experimental results indicate that TiC coatings compared with TiN coatings on $Si_3N_4$ -TiC ceramic have an improved microstructural property, good thermal shock resistance, and good interfacial bonding. However TiN coatings compared with TiC coatings have a low friction coefficient with steel and good chemical stability. It is found by cutting test that coated insert compared with $Si_3N_4$-TiC ceramic have a superior flank and crater wear resistance. And multilayer coating compared with monolayer coating shows a improved wear resistance.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.3
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• pp.224-230
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• 2007

This work is aimed to explore a possibility of using the generalized Lamb waves for nondestructive evaluation of the bonding quality of layered substrates. For this purpose, we prepared two sets of specimens with imperfect bonding at their interfaces; 1) TiN-coated specimens with various wear conditions, and 2) CVD diamond specimens with various cleaning conditions. A dispersion simulation performed for layered substrates with imperfect interfaces are carried out to get the characteristics of dispersion curves that can be used for bonding quality evaluation. Then the characteristics of dispersion curves of the fabricated specimens are experimentally determined by use of an ultrasonic backward radiation measurement technique. The results obtained in the present study show that the lowest velocity mode (Rayleigh-like) of the generalized Lamb waves are sensitively affected by the bonding quality. Therefore, the generalized Lamb waves can be applied for nondestructive evaluation of imperfect bonding quality in various layered substrates.

• Journal of the Korean institute of surface engineering
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• v.24 no.1
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• pp.8-8
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• 1991

To investigate the effects of substrate on transverse-rupture strength(TRS) and bonding strength between substrate and TiC layer coated by CVD, two kinds of substrate (substrate A:WC-9.5wt%Co-MC*[low C], substrate B: WC-6wt% Co-MC*[high C] were studied in terms of Cobalt and C contents respectively. For preparation of test samples the coating parameters of deposition time, deposition temperature and deposition pressure were varied. The result show that the carbon contents in substrates have greater effects on the TRS of the CVD TiC coated cemented carbide than Co contents in substrates.

• Tribology and Lubricants
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• v.6 no.1
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• pp.116-125
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• 1990

An experimental programme was established to determine the wear behaviour of TiN coatings of thickness 1 $\mu$m and 3 $\mu$m. by PECVD with the variation of applied load, sliding velocity and sliding distance. It was shown that oxidation of transferred metal as sliding speed increased formed oxide film so that it contributed in decreasing the wear rate. With the roller-on-disc tribometer employed, the wear rate of the roller specimen was decreased with the increase in sliding distance due to the reduction in effective contact pressure. Finally, the severe cracks concentrated at the trailing edge of contact surface were explained in terms of high tensile stress prevailing at the trailing edge of the contact and were identified as a dominant wear mechanism as well as the strong local welding between coating layer and the counter surface, leading to the debonding of the coating layer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.900-906
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• 2000

Ceramic, PCD and CBN tools are available for the difficult-to-cut-materials such as hardened carbon tool steel, stainless steel, Inconel 718 and etc. Ceramic tools are likely to be chipped and abruptly broken before the appearance of normal wear in turning. Ceramic tools are suitable for continuous in turning, not for intermittent in milling. In this study, TiN/TiCN multi-layer coated ceramic tools were found to restrain the chipping, breaking and early fracture and to increase the critical cutting speed owing to TiN/TiCN multi-layer coating in Arc Ion Plating of PVD method.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.33-38
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• 1998

TiYN coated high speed steel tools have been developed and their tool lifes were assessed. First yttrium alloyed titanium target was manufactured, then using the arc ion plating(AIP) technique TiYN coating was deposited onto high speed steel substrate. Three kinds of varying thickness of TiYN coated tools were prepared. Cutting tests were carried out with theses tools and for comparison with the commercially available uncoated, TiN, TiCN and TiAlN coated tools. During the cutting tests flank wear width vs. cutting time was measured. It has been revealed that the newly developed TiYN coated tools show superior tool life characteristics to others.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.56-68
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• 1997

This work was intended to study the effect of a partial pressure ratio and a total pressure of reactive gases on the properties of TiC$_{x}$N$_{1-x}$ . coated layer. In this regard, various TiC$_{x}$N$_{1-x}$ coatings were synthesized with C2112 and N2 Mixture gas of different compositions by Arc Ion Plating process which has been highlighted for an industrial purpose. It was revealed from colors and X-ray diffraction patterns that the concentration of carbon of a TiC$_{x}$N$_{1-x}$ coating increases with a partial pressure ratio (PC$_{2}$H$_{2}$/PN$_{2}$) as well as a total pressure Of $C_{2}$H$_{2}$ and N$_{2}$ mixture gas. Accordingly, the hardness of TiC$_{x}$N$_{1-x}$ coated layer increased but the adhesion to the substrate of SKH 51 was degraded. On the other hand, the deposition rate was independent of a partial pressure ratio and a total pressure of mixture gas. It was found that a uniform gas distribution is critical for an industrial application since the composition of a coating depends strongly on the location of a substrate inside of the furnace. As a result of milling tests with different TiC$_{x}$N$_{1-x}$ coated end mills, the one which has a low carbon concentration was better than others studied in this work.d in this work.