• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.7
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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.

• Journal of Surface Science and Engineering
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• v.40 no.6
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• pp.279-282
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• 2007

Cr-Mo-Si-C-N coatings were deposited on steel and Si wafer by a hybrid system of AIP and sputtering techniques using Cr, Mo and Si target in $Ar/N_2/CH_4$ gaseous mixture. Instrumental analyses of XRD and XPS revealed that the Cr-Mo-Si-C-N coatings must be a composite consisting of fine(Cr, Mo and Si)(C and N) crystallites and amorphous $Si_3N_4$ and SiC. The hardness value of Cr-Mo-Si-C-N coatings significantly increased from 41 GPa of Cr-Mo-C-N coatings to about 53 GPa with Si content of 9.3 at.% due to the refinement of (Cr, Mo and Si)(C and N) crystallites and the composite microstructure characteristics. A systematic investigation of the microstructures and mechanical properties of Cr-Mo-Si-C-N coatings prepared with various Si contents is reported in this paper.

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.223-227
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• 1996

The effect of ZrC and VC addition on the diffusion induced recrystallization (DIR) of TiC-Cr3C2 has been investigated. With in creasing the amount of added ZrC to Cr3C2 the DIR of TiC was suppressed at the begining and then occurred. On the contrary the DIR was accelerated with the addition of VC to Cr3C2 Because the lattice parameters of (Ti, Cr)C and (Ti,V)C are smaller and that of (Ti, Zr)C is larger than that of TiC the lattice parameter of (Ti,Cr,Zr)C is expected to be similar to that of TiC,. The results indicate that the strain energy due to lattice mismatch between TiC and solid-solution carbide is the driving force of the observed energy due to lattice mismatch between TiC and solid-solution carbide is the driving force of the observed DIR.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.184-185
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• 2009

하이브리드 코팅 시스템을 이용하여 CrN 을 기초로 3성분계 코팅을 합성한다. 이번 연구는 C를 첨가한 음이온 고용경화와 Mo를 첨가한 양이온 고용경화의 영향이 미세구조와 기계적 성질에 미치는 영향을 알아보는 것이다. Cr-C-N 과 Cr-Mo-N 코팅은 23, 43GPa의 최대 경도 값을 가진다. 이 경도강화는 고용강화로 설명할 수 있다.

• Journal of the Korean Ceramic Society
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• v.31 no.7
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• pp.767-771
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• 1994

In a salb-preheating furnace of steel-making industry, the oxidation/degradation behavior of Cr3C2 ceramic composited dkid button reaction with scale in Fe-oxide system occurs and was thermodynamically examined. The reaction of scale with Cr3C2 skid button produces Cr3C2(s) and C(s), and Co gas is then evolved from the reaction of C(s) with Fe-scale. Cr3C2(s) from oxidation of Cr3C2(s) reacted with Fe-oxide(s) becomes high-melting chromite. The chromite acts as protection layer against further oxidation and improves resistance of the reaction of Cr3C2 skid button with Fe-scale.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.119-120
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• 2013

공구, 다이몰드 등에 널리 쓰이는 TiC, TiN, CrN, TiCrN, TiAlN 코팅의 산화특성을 비교하기 위하여 $600^{\circ}C-900^{\circ}C$에서 대기중 산화시험을 실시하였다. 내산화성은 (TiC, TiN), TiAlN, TiCrN, CrN 코팅의 순서로 증가하였다. 코팅원소중 Ti는 $TiO_2$로, Cr은 $Cr_2O_3$로, Al은 $Al_2O_3$로 산화되었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.714-719
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• 2005

NiCr thin film was deposited by DC magnetron sputtering on $A;_2O_3$/Si substrate with NiCr (80:20) alloy target. NiCr thin films were annealed at $300^{\circ}C,\;400^{\circ}C,\;500^{\circ}C,\;600^{\circ}C,\;and\;700^{\circ}C$ for 6 hr in $H_2$ after annealing at $500^{\circ}C$ for 6hr in air atmosphere, respectively. To analyze NiCr thin film properties, the changes of its micro structure were Investigated through field emission scanning electron microscope (FESEM). X-ray photoelectron spectroscopy (XPS) was used to analyze a surface of NiCr thin film. Resistance of NiCr thin film was measured by 4-point probe technique. The generated heats were measured by infrared thermometer through the application of DC voltage (5 V/l2 V). NiCr thin film treated by gradational double annealing process had uniform and small grains. Maximum temperature generated heat by NiCr micro heater was $173^{\circ}C$. We expect that our results will be a useful reference in the realization of NiCr micro heater.

• Journal of the Korean Magnetics Society
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• v.3 no.3
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• pp.215-220
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• 1993

Microstructural dependence of magnetic property of RF/DC sputtered $Co_{69.0}Ni_{18.5}Cr_{12.5}/Cr$ double layer thin film was studied. Grain size was found to be decreased with substrate temperature in the range of $100-200^{\circ}C$ and Cr underlayer thickness(from $500\;{\AA}-2000\;{\AA}$). The peaks (200) and (1120) of X-ray diffraction patterns were evidently grown with the substrate temperature for the Cr underlayer and magnetic layer, respectively. The CoNiCr magnetic layer was found to be well epitaxialy grown on Cr underlayer, and subsequently the coercivity was enhanced.

• Journal of the Korean Ceramic Society
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• v.35 no.3
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• pp.231-238
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• 1998

Cr3C2 -dispersed TiC composites were prepared via HPCS(high pressure-self combustion sintering) pro-cess using mixtures of Ti, Cr and a carbon source for the purpose of increasing the facture toughness and sinterability of TiC. In this study the microstructure and properties of the composites were investigated in terms of relation to the carbon source the particle size of Ti and the amount of Cr. It was found that car-bon black was the most effective carbon source among the various carbon sources tested and the reaction was more effective as the particle size of Ti decreased. Among the sintered composites of Ti-C-Cr system the one with 30wt% Cr showed the best physical properties with 0.5% in apparent porosity 98.8% in re-lative density 18.2 GPa in hardness and 4.46 MPa.m1/2 in fracture toughness. In addition it was observed that the lattice constant of TiC decreased gradually with increasing the amount of Cr.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.561-571
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• 1999

Microstructure and mechanical properties of five Cr-Mo steels for nuclear industry applications have been investigated. Transmission electron microscopy, energy dispersive spectrometer, differential scanning calorimeter, hardness, tensile, and impact test were used to evaluate the Cr and W effect on the microstructure and mechanical properties. Microstructures of Cr-Mo steels after tempering are classified into three types : bainitic 2.25Cr-lMo steel, martensitic Mod.9Cr-lMo, HT9M, and HT9W steels, and dual phase HT9 steel. The majority of the precipitates were found to be M$_{23}$C$_{6}$ carbides. As minor phases, fine needle-like V(C,N), spherical NbC, fine needle-like Cr-rich Cr$_2$N, and Cr-rich M$_{7}$C$_3$were also found. Addition of 2wt.% W in Cr-Mo steels retarded the formation of subgrain and dissolution of Cr$_2$N precipitates. Hardness and ultimate tensile strength increased with increasing Cr content. Though Cr content of HT9W steel was lower than that of HT9 steel, the hardness of HT9W was higher due to the higher W content. W added HT9W steel had the highest ultimate tensile strength above $600^{\circ}C$. But impact toughness of W added steel (HT9W) and high Cr steel (HT9) was low.w.w.