• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.47-52
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• 2005

In this paper, the effect of TiN-coating on product quality such as dimensional accuracy and surface roughness is experimentally investigated. A punch of SKD11 material in cold forging an automotive bearing shaft and its related process found in a cold forging company are selected as the test example. The effect of TiN-coating is revealed in a quantitative manner. It is to be noted that TiN-coating is effective in controlling the dimensional accuracy and surface roughness as well as in increasing tool lift.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.143-147
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• 2004

In this paper, effect of TiN-coating on product quality such as dimensional accuracy and surface roughness is experimentally investigated. A punch of SKD11 material in cold forging of an automotive bearing shaft and its related process found in a cold forging company ate selected as the test example. The effect of TiN-coating is revealed in a quantitative manner. It is to be noted that TiN-coating is effective in controlling the dimensional accuracy and surface roughness as well as in increasing tool lift.

• Tribology and Lubricants
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• v.17 no.6
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• pp.453-458
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• 2001

The fretting wear of a nuclear fuel rod it a dangerous phenomenon. In this study, TiN coating was used to reduce the fretting wear of Zircaloy-4 tube, a nuclear fuel rod cladding material. TiN coating is probably one of the molt frequently and successfully used PVD coatings for the mitigation of fretting wear. The fretting tester was designed and manufactured for this experiment. The number of cycles, slip amplitude and normal load were selected as main factors of fretting wear. The results of this research showed that wear volume was improved 1.3∼3.2 times with TiN coating. The worn surfaces were observed by SEM. Wear mechanism at lower slip amplitude was the brittle cracks and rupture of TiN coating. However, adhesive and abrasive wear were mainly observed on most surfaces at higher slip amplitude.

• Korean Journal of Materials Research
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• v.13 no.7
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• pp.420-423
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• 2003

Coatings of TiCrN ion-plated on a steel substrate was oxidized at $800^{\circ}C$ in air, and their oxidation mechanism was presented. During oxidation, substrate elements and Ti and Cr in the coating always diffused outwardly to form the oxide scale. Simultaneously, oxygen from the atmosphere diffused inward1y to react with Ti and Cr to form $TiO_2$and $Cr_2$$O_3$, respectively. Also, the counter-diffusion of cations and oxygen resulted in some oxygen dissolution in the unoxidized TiCrN coating, and Fe dissolution in the oxide scale. When the Ti content in the coating was high, the $TiO_2$-forming tendency was strong, while when the Cr content was high, the $Cr_2$$O_3$-forming tendency was strong.

• Tribology and Lubricants
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• v.37 no.2
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• pp.54-61
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• 2021

The effect of the sand blasting before TiAlN coating in the manufacture of WC hard metal alloy tips have been studied. For four different tips, according to the status of processing of the sand blasting and the coating, residual stress measurement by X-ray diffraction and several tests for mechanical properties have been conducted. The results suggest that there was no difference in static mechanical properties, such as hardness, surface roughness and elastic modulus, between two coatings. Furthermore, compressive residual stress was generated equally on their surfaces. Additionally, the compressive residual stress in substrate WC was found to increase greatly when subjected to sand blasting treatment. However, the compressive residual stress decrease after coating regardless of sand blasting treatment. Nevertheless, it is confirmed that the compressive residual stress generated in the coating after sand blasting is less than that in the non-sandblasting coating. This was attributed to the plastic deformation occurring in the WC substrate during coating after sand blasting. In contrast to the scratch test results, sand blasting was assumed to have a negative effect on the adhesion between the coating and substrate. This is because there is a high possibility of microcracks due to plastic deformation in the WC substrate under the coating after sand blasting.

• Journal of Powder Materials
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• v.15 no.2
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• pp.101-106
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• 2008

The objective of the present study is to investigate the increase in the functional characteristics of a substrate by the formation of a thin coating layer. Thin coating layers of $Ti_5Si_3$ have high potential because $Ti_5Si_3$ exhibits high hardness. Shock induced reaction synthesis is an attractive fabrication technique to synthesize uniform coating layer by controlling the shock wave. Ti and Si powders to form $Ti_5Si_3$ using shock induced reaction synthesis, were mixed using high-energy ball mill into small scale. The positive effect of this technique is highly functional coating layer on the substrate due to ultra fine substructure, which improves the bonding strength. These materials are in great demand as heat resisting, structural and corrosion resistant materials. Thin $Ti_5Si_3$ coating layer was successfully recovered and showed high Vickers' hardness (Hv=1183). Characterization studies on microstructure revealed a fairly uniform distribution of powders with good interfacial integrity between the powders and the substrate.

• Journal of the Korean institute of surface engineering
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• v.42 no.4
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• pp.157-160
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• 2009

Many fundamental studies have been carried out regarding waste water and hazardous gas treatments technologies using the photolysis effect of $TiO_2$. However, a permanent use of $TiO_2$ particles immobilized using organic or organic-inorganic binders is impossible. In this study, Ni-$TiO_2$ composite coating was produced by electroless plating to trap $TiO_2$ particles in the Ni coating layer. The electroless plating was performed in the bath solutions with three different concentrations of $TiO_2$ particles : 10 g/l, 20 g/l, and 40 g/l. The surface and photolytic characteristics of the coating layer was investigated by the use of SEM, a scratch tester, and an UV-Visible spectrophotometer. The results showed that the amounts of immobilized $TiO_2$ particles and the photolytic rate of the coating increased with the initial content of $TiO_2$ particles in the electroless bath. In addition, the photolytic rate of the Ni-$TiO_2$ composite coating was remarkably promoted by etching process in 10% HCl solution.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.435-444
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• 2001

WC-( $Ti_{1-x}$ A $l_{x}$) N coatings of constant changing Al concentration were deposited on S45C substrates by high-ionization sputtered PVD method. The Al concentration could be controlled by using evaporation source for Al and fixing the evaporation rate of the metals (i.e, WC- $Ti_{0.86}$A $l_{0.14}$N, WC- $Ti_{0.72}$A $l_{0.28}$N, and WC- $Ti_{0.58}$A $l_{0.42}$N). The corrosion behavior of WC-( $Ti_{1-x}$ A $l_{x}$)N coatings in a deaerated 3.5% NaCl solution was investigated by electrochemical corrosion tests and surface analyses. The measured galvanic corrosion currents between coating and substrate indicated that WC- $Ti_{0.72}$A $l_{0.28}$N coating showed the best resistance of the coating tested. The results of potentiodynamic polarization tests showed that the WC- $Ti_{0.72}$A $l_{0.28}$N coating deposited with 32W/c $m^2$ of Al target revealed higher corrosion resistance. This indicated that the WC- $Ti_{0.72}$A $l_{0.28}$N coating is effective in improving corrosion resistance. In EIS, the WC- $Ti_{0.72}$A $l_{0.28}$N coating showed one time constant loop and increased a polarization resistance of coating ( $R_{coat}$) relative to other samples. Compositional variations of WC-( $Ti_{1-x}$ A $l_{x}$)N coatings were analyzed by EDS and XRD analysis was performed to evaluate the crystal structure and compounds formation behavior. Surface morphologies of the films were observed using SEM and AFM. Scratch test was performed to measure film adhesion strength.strength. adhesion strength.strength.

• Journal of the Korean institute of surface engineering
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• v.40 no.6
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• pp.254-257
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• 2007

TiN coating on tool steel has been widely used for the improvement of durability of tools. In this work, radical nitriding(RN) is carried out on SKD61 at $450^{\circ}C$ for 5 hours in the ammonia gas pressure $2.7{\times}10^3\;Pa$. The TiN coating is carried out by arc ion plating(AIP) with the process parameters: arc power 150 A, bias voltage -50V, coating time 40 minutes and nitrogen gas pressure $4{\times}10^3\;Pa$. Hardness, elastic modulus, friction coefficient and adhesion of TiN coating on substrates of both TiN/SKD61 and TiN/RN SKD61 coatings are investigated comparatively. The primary crystalline faces of TiN surface are(200) and(111) for TiN/SKD61 and TiN/RN SKD61 respectively. In addition to the primary phase, Fe phase exists in TiN/SKD61 coating, but not in TIN/RN SKD61. The hardness of TiN/RN SKD61 is about 700 Hv, 250 Hv(56%) higher than that of TiN/SKD61 at the near interface of TiN and substrates. At the TiN surface, hardness of TiN/RN SKD61 is 2,149 Hv, 71 Hv(3%) higher than that of TiN/SKD61. The elastic modulus of TiN coating is improved to 26.7 GPa(6%) by radical nitriding. The adhesion is improved by the RN coating showing no spalling. buckling and chipping on the scratch test track which are shown on the non-RN TiN/SKD61.

• Korean Journal of Materials Research
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• v.25 no.5
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• pp.253-257
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• 2015

The implanting of metal products is performed with numerous surface treatments because of toxicity and adhesion. Recently, the surface modification of metal products has been actively studied by coating the surface of the TiC or TiN film. We prepared a Ti(10%)Ag Target which may be used in dental oral material by, using the AIP(arc ion plating) system TiAgN coating layer that was deposited on Ti g.23. The purpose of this study was to establish the optimal bias voltage conditions of the coated TiAgN layer formed by the AIP process. The TiAgN coatings were prepared with different bias voltage parameters (0V to -500V) to investigate the effect of bias voltage on their mechanical and chemical properties. The SEM(scanning electron microscope), EDS(energy dispersive X-ray spectrometer), XRD(X-ray diffraction), micro-hardness, and potentiodynamic polarization were measured and the surface characteristics of the TiAgN coating layers were evaluated. The TiAgN coating layer had different mechanical characteristics based on the bias voltage, which also showed differences in thickness and composition.