• 한국재료학회지
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• 제12권8호
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• pp.669-675
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• 2002

CrN film coated by AIP method, improved the mechanical properties (Hardness, Roughness, wear and fatigue) of Ti-6Al-4V alloy. The properties were studied using GXRD, XPS, Hardness, Roughness, wear and fatigue testers. CrN thin film thickness was about 7.5$\mu\textrm{m}$ and grew with (111) orientation. Hardness of CrN thin film was very high (Hv 1390) and roughness of the surface layer was greatly improved (Ra=0.063$\mu\textrm{m}$) compared with matrix alloy (Ra=0.321$\mu\textrm{m}$). Such changes of hardness and roughness could be contributed to improving the wear resistance and fatigue life. Striation like pattern with dimples and voids, a typical fatigue fracture mode, was observed throughout the specimen.

• 한국기계가공학회지
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• 제8권4호
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• pp.122-128
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• 2009

The purpose of this study is to show the friction and wear characteristics on the vapor deposited coating layers on the SCM415 steel. In this research, frictional wear characteristic of coating materials such as CrN, AlCrN, WC/C was investigated under room temperature, normal air pressure and nothing lubricating condition. Therefore this study carried out research on the friction coefficient, micro hardness(Hv), roughness, EPMA on the vapor deposited coating layers on the SCM415 steel.

• 한국표면공학회지
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• 제24권4호
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• pp.222-229
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• 1991

The oxidation behavior of Ni-6wt.% Cr alloys with various concentration of alumina dispersions(5vol.% 10vol.%) was determined at 1000 and 110$0^{\circ}C$ in oxygen of 1 atm. pressure. Some general observations were ascertained. These include: (a) the addition of alumina dispersoids significantly increased the oxidation resistance of Ni-6wt.% Cr alloy; (b) the rate of oxidation was distinctly decreased as a function of the volume percent of oxide dispersion; and (c) the presence of alumina dispersions promoted the formation of continous, protective Cr2O3 layer at 6 wt.% Cr.

• 한국전기전자재료학회논문지
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• 제13권5호
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• pp.444-450
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• 2000

We prepared Co-Cr thin film for perpendicular magnetic recording media with facing targets sputtering system(FTS system) which can deposit a high quality thin film in plasma-free state and wide range of working pressure. The effect of sputtering conditions(argon gas pressure and substrate temperature) on the magnetic and the crystallographic characteristic of Co-Cr thin film was investigated. And the variation of perpendicular coercivity with the variation of film thickness was studied. As a result we obtained the high perpendicular coercivity of 1900Oe and the good dispersion angle of c-axis($\Delta$$\theta$$_{50}$) of 5$^{\circ}$on the film thickness of 100nm for the promising recording layer of perpendicular magnetic recording media.c recording media.a.

• 한국표면공학회지
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• 제27권1호
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• pp.3-11
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• 1994

Cyclic hot corrosion studies have been carried out on(82~94) wt. % Fe-(5, 10, 15) wt. % Cr alloys con-taining either (1, 3)wt. % of Si or Pt as minor alloying elements in molten salts of($Na_2SO_4$+NaCl) between 820 and $920^{\circ}C$. Si or Pt decreased corrosion rate with the most pronounced effect being observed for alloys having 15wt. %Cr. Especially, as Si or Pt contents are increased from 1 to 3 wt. %, improved corrosion resistance was obtained. The beneficial effect of Si addition is due to the presence of the Si-rich second phase along the grain boundaries as well as the formation of the protective $SiO_2$layer between substrates and oxide scale. The Pt addition also increased the corrosion resistance by enhancing the formation ($Cr_2O_3$+layers and by increasing the adherence of the oxide scale.

• 대한치과기공학회지
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• 제33권3호
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• pp.185-192
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• 2011

Purpose: This study was to evaluate the shear bond strength of the ceramic fused to Ni-Cr alloy(Bellabond plus) and Co-Cr alloy(Wirobond C) by heat treatment. Methods: Metal specimens were divided into 5 groups for each alloy according to heat treatment conditions prior to porcelain application. Fifteen specimens from each group were subjected to a shear load a universal testing machine using a 0.1mm/min cross-head speed and one specimen from each group was observed with EDX line profile. Results: The diffusion of metal oxide observed far in the specimen heat treated than no heat treated in the opaque layer. The shear bond strength measured highest to BP3(50.50MPa), WC2(50.49MPa) groups and measured lowest from BP1(35.1MPaa), WC1(39.66MPa) groups which were not treated with heat, and there was a significant difference (p<0.05). Conclusion: The shear bond strength of Ni-Cr alloy(Bellabond plus) and Co-Cr alloy(Wirobond C) measured similar 5 groups all.

• 한국표면공학회지
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• 제44권6호
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• pp.269-276
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• 2011

Phase evolution and tribological behavior of Cr-Mo-N multi compositional films with different interlayer were investigated. The films were deposited by hybrid PVD (Physical Vapor Deposition) system consisted of dc unbalanced magnetron (UBM) sputtering and arc ion plating (AIP) sources. A pure molybdenum (Mo) was used as sputtering target and also a pure Cr was used as AIP target to form the Cr-Mo-N films. Various growth planes were found, no textured surface, in all of the multi composition films. Maximum value of microhardness was measured in Cr-Mo-N film with Mo interlayer as 29 GPa. Composition film was mainly showed the aspect of the adhesive wear than CrN film. The friction coefficient was decreased from 0.6 for pure CrN coating to 0.35 for Cr-Mo-N film with Mo interlayer. This result may come from the formation of metal oxide tribo-layer which is known as solid lubricant during the wear test.

• 한국전기전자재료학회논문지
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• 제31권7호
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• pp.475-480
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• 2018

We investigated the tribological properties of amorphous carbon (a-C) films deposited with CrC interlayers of various thicknesses as the adhesive layer. A-C and CrC thin films were deposited using the unbalanced magnetron (UBM) sputtering method with graphite and chromium as the targets. CrC films as the interlayer were fabricated under a-C films, and various structural, surface, and tribological properties of a-C films deposited with various CrC interlayer thicknesses were investigated. With various CrC interlayer thicknesses under a-C films, the tribological properties of CrC/a-C films were improved; the increased film thickness exhibited a maximum high hardness of over 27.5 GPa, high elastic modulus of over 242 GPa, critical load of 31 N, residual stress of 1.85 GPa, and a smooth surface below 0.09 nm at the condition of 30-nm CrC thickness.

• 대한치과기공학회지
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• 제35권4호
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• pp.353-358
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• 2013

Purpose: This study was observation shear bonding strength by compositional change and firing step of a Ni-Cr alloy for porcelain fused metal crown. The aim of study was to suggest the material for firing step of Ni71-Cr14 alloy to development of alloy for porcelain fused to metal crown. Methods: The test was on the two kinds of Ni-Cr alloy specimens. The surfaces of two alloys were analyzed by EDX in order to observe oxide characteristic. And the shear test was performed by MTS. Results: The surface property and oxide characteristic analysis of oxide layer, weight percentage of Element O within $Ni_{71}Cr_{14}$ alloy measured 23.32wt%, and $Ni_{59}Cr_{24}$ alloy was measured 23.03wt%. And the maximum shear bonding strength was measured 58.02MPa between $Ni_{59}Cr_{24}$ alloy and vintage halo(H4 group). Conclusion: The surface property and oxide characteristic three kind of Ni-Cr alloy was similar. and shear bonding strength showed the highest bonding strength in H4 specimens.

• 한국표면공학회지
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• 제34권2호
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• pp.125-134
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• 2001

($Ti_{1-x}$ $Cr_{x}$ )N coatings were deposited by an ion-plating method in a reactor with two separate metal sources, Ti and Cr. Ti was evaporated using an electron beam, while Cr evaporation was carried out by resistant heating. The Ti and Cr concentrations in the coatings were controlled by the Ti and Cr evaporation ratio. The coating hardness increased with increasing the Cr content(x) and showed a maximum value of 6,000 HK at around x=0.8. The critical load of the coatings, measured by the scratch test, was around 30 N. The wear resistance properties of the ($Ti_{1-x}$$Cr_{ x}$)N coatings were evaluated using a CSEM pin-on-disk type tribometer. A Cr-steel ball as well as a SiC ball, which had hardness values of 590 HK and 2,600 HK respectively, were used as the pin. After the wear test, the surface morphology, roughness and the concentration of the coatings were investigated, with the main focus being on the effect of wear debris and the transferred layer on the wear behavior.