• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.3
• /
• pp.432-436
• /
• 2007

We have studied on the tribological characteristics of Plasma Vapour Deposition(PVD) coating method in Automotive Structural Materials. Coating materials were deposited by the Titanium carbide(TiC) and Titanium nitride(TiN). An experimental process was established to determine the tribological characteristics of friction and wear behaviour with the variation of applied load, temperature and the time with the Falex friction and wear test machine. It was improved that when the surface modification of hard coatings(TiC, TiN) was deposited steel, the tribological characteristics become better. It is argued that it is improved because of excellence of the anti-wear, the extreme pressure properties and tile heat stability.

• Journal of the Korean institute of surface engineering
• /
• v.35 no.6
• /
• pp.415-421
• /
• 2002

Ti-Si-N coating layers were codeposited on silicon wafer substrates by a DC reactive magnetron sputtering technique using separate titanium and silicon targets in $N_2$/Ar gas mixtures. The oxidation behavior of Ti-Si-N coating layers containing 4.0 at.%, 10.0 at.%, and 27.3 at.% Si was investigated at temperatures ranging from 600 to $960^{\circ}C$. The coating layers containing 4.0 at.% Si became fast oxidized from $600^{\circ}C$ while the coating layers containing 10.0 at.% Si had oxidation resistance up to $800^{\circ}C$. It was concluded that an increase in Si content to a level of 10.0 at.% led to the formation of finer TiN grains and a uniformly distributed amorphous Si3N4 phase along grain boundaries, which acted as efficient diffusion barriers against oxidation. However, the coating layers containing 27.3 at.% Si showed relatively low oxidation resistance compared with those containing 10.0 at.% Si. This phenomenon would be explained by the existence of free Si which was not nitrified in the coating layers containing 27.3 at.% Si.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.5
• /
• pp.848-854
• /
• 2012

SCM420 steel cutting gear to improve the durability is quenched. When quenching, increases surface hardness, a change of the physical properties and machinability or fall. This study, using a solid carbide hobs skiving hobbing gear cutting finishing. And cutting tool solid carbide TiAlN coating hove when TiAlN coating on the surface of multi-con polishing hob conducted aero lap nano polishing for each cutting. Experimental results conducted aero lap nano coating on the surface polishing tool machinability was excellent. And aero lap nano polishing tool results were reduced 2.5 times the tool wear compared to TiAlN coated tools. Excellent results were 1.42 times longer tool life.

• Journal of the Korean institute of surface engineering
• /
• v.31 no.6
• /
• pp.400-406
• /
• 1998

Tool life characteristics were investigated for the TiN coated (PVD) tungsten carbide cutting tools to improve the tool life Experimental variables for Tin coating were coating time and cathode bias voltage and cuting variables were cutting speed and feel rate. As a experiment result, TiN coated tool was extended about from 2.14 to 2.7 times than that of not coated tungsten carbide tools. Also, coating thinkness is much affected to tool life.

• Journal of the Korean institute of surface engineering
• /
• v.52 no.3
• /
• pp.163-170
• /
• 2019

Durability of instrument is one of the most important factor to ensure accurate treatment and decrease failure for the orthopedic surgical operation. Normally, a set-screw driver tip has been processed with hard coating for their higher durability and wear resistance. And several surface modification methods were obtained such as titanium nitride (TiN) coating, diamond like carbon coating, other nitriding, and etc. In this study, we have surface modified on set-screw driver tip with TiN and DLC, investigated whether the TiN and DLC coatings affect the mechanical properties and durability of the set-screw driver tip in the pedicle screw system. The surface morphologies were observed with scanning-electron microscopy (SEM), and the static/dynamic torsional properties were investigated with universal testing machine based on ASTM F543. Coating thickness of each coatings were commonly around $1^{\circ}C$. Static torsional stiffness, and ultimate torque values for DLC and TiN coated samples were significantly higher than those of non-coated sample by the pared T-test. Surface morphology of after the dynamic torsional test was more clean with less scratch or friction traces from DLC coating than that of TiN coating and non-coated sample.

• Journal of the Korean Society for Heat Treatment
• /
• v.19 no.4
• /
• pp.225-229
• /
• 2006

TiAlN coatings are available in various industry fields as a wear resistant coating for high-speed machining, due to its high hardness, excellent oxidation and corrosion resistance. The corrosion resistance of TiAlN multilayer coatings is better than that of single TiN coatings. Most of TiAlN coated layers were formed by heat treatment of coating layers with a non-stoichiometric $Ti_xAl_{1-x}N$. In this study, TiAlN coated layer was prepared by R.F magnetron sputtering and investigated the thermal behavior for heat treatment at various temperature in tube furnace. The formation of large particles with porous microstructure and phase change from HCP to FCC were observed on coated layer during heat treatment over $850^{\circ}C$ and it reduced the corrosion resistance of coated TiAlN layers.

• Journal of the Korean institute of surface engineering
• /
• v.42 no.2
• /
• pp.73-78
• /
• 2009

Quinary Ti-Al-Si-C-N films were successfully synthesized on SUS 304 substrates and Si wafers by a hybrid coating system combining an arc ion plating technique and a DC reactive magnetron sputtering technique. In this work, the effect of Si content on the microstructure and mechanical properties of Ti-Al-C-N films were systematically investigated. It was revealed that the microstructure of Ti-Al-Si-C-N coatings changed from a columnar to a nano-composite by the Si addition. Due to the nanocomposite microstructure of Ti-Al-Si-C-N coatings, the microhardness of The Ti-Al-Si-C-N coatings significantly increased up to 56 GPa. In addition the average friction coefficients of Ti-Al-Si-C-N coatings were remarkably decreased with Si addition. Therefore, Ti-Al-Si-C-N coatings can be applicable as next-generation hard-coating materials due to their improved hybrid mechanical properties.

• Journal of the Korean institute of surface engineering
• /
• v.41 no.6
• /
• pp.292-300
• /
• 2008

Dental implant system is composed of abutment, abutment screw and implant fixture connected with screw. The problems of loosening/tightening and stability of abutment screw depend on surface characteristics, like a surface roughness, coating materials and friction resistance and so on. For this reason, surface treatment of abutment screw has been remained research problem in prosthodontics. The purpose of this study was to investigate the stability of TiN and WC coated dental abutment screw, abutment screw was used, respectively, for experiment. For improving the surface characteristics, TiN and WC film coating was carried out on the abutment screw using EB-PVD and sputtering, respectively. In order to observe the coating surface of abutment screw, surfaces of specimens were characterized, using field emission scanning electron microscope(FE-SEM) and energy dispersive x-ray spectroscopy(EDS). The stability of TiN and WC coated abutment screw was evaluated by potentiodynamic, and cyclic potentiodynamic polarization method in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The corrosion potential of TiN coated specimen was higher than those of WC coated and non-coated abutment screw. Whereas, corrosion current density of TiN coated screws was lower than those of WC coated and non-coated abutment screw. The stability of screw decreased as following order; TiN coating, WC coating and non-coated screw. The pitting potentials of TiN and WC coated specimens were higher than that of non-coated abutment screw, but repassivation potential of WC coated specimen was lower than those of TiN coated and non-coated abutment screws due to breakdown of coated film. The degree of local ion dissolution on the surface increased in the order of TiN coated, non-coated and WC coated screws.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.3 no.2
• /
• pp.115-119
• /
• 2002

This study was performed to improve mechanical properties of rotor and bushing materials. SACD and SKD11 steels as rotor and bushing materials were investigated. Gas nitriding and TiN coating were carried out on SACM and SKD11 steels. TiN coating was deposited on SKD11 steel by reactive sputtering process. This coated layer was picked off during the operation because of insufficient adhesion. Gas nitriding was carried out on SACM and SKD11 steels in an ammonia atmosphere at 51$0^{\circ}C$ for 72 hrs. These gas nitrided parts showed good mechanical properties. SKD11 steels were heat-treated to obtain optimum carbide size and distribution. As a results, the hardness increased.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.3
• /
• pp.100-107
• /
• 2011

To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process in great detail. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail, using in-situ system. In this study, based on the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. Consequently, four modes were revealed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. Sc(Severity of contact) can clarify transition condition of those microscopic wear modes.