• 마이크로전자및패키징학회지
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• 제14권1호
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• pp.61-68
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• 2007

임베디드 PCB 기판내 유전체 재료인 Atomic Layer Deposition(ALD) $Al_2O_3$ 박막과 전극재료인 스퍼터 증착된 Cu박막 사이의 계면접착력을 $90^{\circ}$ 필 테스트방법으로 측정하여 순수 빔 굽힘을 가정한 에너지 평형 해석을 통하여 계면파괴에너지를 구하였다. $Cu/Al_2O_3$의 계면파괴에너지(${\Gamma}$)는 매우 약하여 측정할 수 없었으나, 접착력 향상층 Cr 박막을 삽입하여 $Cr/Al_2O_3$의 계면파괴에너지는 $10.8{\pm}5.5g/mm$를 얻었다. $Al_2O_3$ 표면에 $0.123W/cm^2$ 의 power density로 2분간 $Ar^+$ RF 플라즈마 전처리를 하고 Cr박막을 삽입한 $Cr/Al_2O_3$ 계면파괴에너지는 $39.8{\pm}3.2g/mm$으로 매우 크게 증가하였는데, 이는 $Ar^+$ RF 플라즈마 전처리에 따른 mechanical interlocking효과와 Cr-O 화학결합 효과가 동시에 기여한 것으로 생각된다.

• 마이크로전자및패키징학회지
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• 제10권2호
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• pp.39-47
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• 2003

감광성 폴리이미드 위에 Cr을 RF 바이어스 스퍼터링 및 RF클리닝 후 DC 스퍼터링한 Cr/폴리이미드의 계면을 TEM으로 관찰하였다. RF power 밀도를 $0.13W/cm^2$에서 $2.12W/cm^2$로 증가시키면서 RF클리닝을 실시한 결과 폴리이미드의 에칭 양상이 둥근 모양에서 뾰족한 모양으로 변하였고 이방성 에칭으로 인해 거칠기가 크게 증가하였다. RF 바이어스 스퍼터링의 경우 RF power를 올리는 동안 RF 클리닝에 의해 폴리이미드가 에칭되었고, 에칭된 부분에 Cr이 증착된 계면을 단면으로 관찰한 결과 Cr과 폴리이미드가 겹쳐져서 혼합된 것처럼 보였다. 그러나 RF power를 올리는 시간을 단축시켜 Cr을 바이어스 스퍼터링했을 때에는 계면이 분명하게 관찰되어 Cr의 implantation이 일어나지 않았음을 알 수 있었다. RF 클리닝한 Cu/Cr/Polyimide를 필 테스트한 결과 짧은 시간의 RF 클리닝으로도 접착력이 크게 증가하였다. 그러므로 RF power를 올리는 동안 실시되었던 RF 클리닝이 RF 바이어스 스퍼터링한 Cr/Polyimide의 접착력 향상에 영향을 주었을 것으로 예상된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 추계학술발표 개요집
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• pp.116-118
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• 1997

• 한국결정성장학회지
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• 제21권6호
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• pp.235-239
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• 2011

두 가지 조성의 TiCrN 코팅층(Ti : Cr = 20 : 80 및 5 : 95wt%)을 Inconel 617 합금 위에 증착하고, 1000oC까지의 온도영역에서 TiCrN 코팅이 Inconel 617 합금의 고온안정성에 미치는 영향을 조사하였다. XRD 분석과 미세구조 관찰을 통해 표면으로의 불균일한 Cr 확산이 TiCrN 층에 의해 억제되었음을 알 수 있었다. 그 결과 Inconel 617의 열산화 저항성이 현저하게 향상되었음을 확인하였다.

• 한국재료학회지
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• 제11권1호
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• pp.34-38
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• 2001

Fe-28%Al($Fe_3Al$)과 Fe-28%Al-4%Cr($Fe_3Al-4Cr$) 금속간화합물을 대기중 1073, 1273, 1473k의 온도에서 최고 17일까지 장시간 산화시켰다. $Fe_3Al-4Cr$의 산화저항은 근본적으로 $Fe_3Al$과 거의 비슷하거나, 약간 우수하였다. $Fe_3Al$ 위에 형성된 산화물은 거의 순수한 ${\alpha}-AL_2O_3$로만 구성되어 있었으며, $Fe_3Al-4Cr$ 위에 형성된 산화물은 약간의 Fe와 Cr 이온이 고용된 ${\alpha}-AL_2O_3$로 구성되어 있었다. 외부산화막을 형성하기 위해 모재원소의 외부확산에 의해 산화물-모재 계면에는 Kirkendall 기공이 존재하였다. $Fe_3Al(-4Cr)$ 표면에 형성된 산화막은 1273k가지는 비교적 얇고 치밀하였으나, 1473k에서 산화막의 박리와 함께 상대적으로 큰 무게증가가 발생하였다.

• 한국분말재료학회지
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• 제25권5호
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• pp.408-414
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• 2018

This study investigates the microstructure and wear properties of cermet (ceramic + metal) coating materials manufactured using high velocity oxygen fuel (HVOF) process. Three types of HVOF coating layers are formed by depositing WC-12Co, WC-20Cr-7Ni, and Cr3C2-20NiCr (wt.%) powders on S45C steel substrate. The porosities of the coating layers are $1{\pm}0.5%$ for all three specimens. Microstructural analysis confirms the formation of second carbide phases of $W_2C$, $Co_6W_6C$, and $Cr_7C_3$ owing to decarburizing of WC phases on WC-based coating layers. In the case of WC-12Co coating, which has a high ratio of $W_2C$ phase with high brittleness, the interface property between the carbide and the metal binder slightly decreases. In the $Cr_3C_2-20CrNi$ coating layer, decarburizing almost does not occur, but fine cavities exist between the splats. The wear loss occurs in the descending order of $Cr_3C_2-20NiCr$, WC-12Co, and WC-20Cr-7Ni, where WC-20Cr-7Ni achieves the highest wear resistance property. It can be inferred that the ratio of the carbide and the binding properties between carbide-binder and binder-binder in a cermet coating material manufactured with HVOF as the primary factors determine the wear properties of the cermet coating material.

• 대한치과기공학회지
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• 제35권4호
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• pp.359-364
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• 2013

Purpose: This study was to observe characteristic of metal oxidation and bonding strength according to composition of Ni-Cr alloy for porcelain fused to metal crown. The three kinds of Ni-Cr alloy with different composition ratio of parent metal were observed general properties and chemical properties of each alloy surface and measured the shear bonding strength between ceramic and each alloys. The aim of study was to suggest the material for design of parent metal's composition ratio to development of alloy for porcelain fused to metal crown. Methods: The three kinds of alloy as test specimen was Ni(59wt%)-Cr(24wt%), Ni(67wt.%)-Cr(16wt.%) alloy and Ni(71wt%)-Cr(12wt%)alloy. The oxide on surface was observed by EDX. 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 $Ni_{59}Cr_{24}$ alloy measured 23.03wt%, $Ni_{67}Cr_{16}$ alloy measured 21.13wt% and $Ni_{71}Cr_{12}$ alloy was measured 48.55wt%. And the maximum shear bonding strength was measured 58.02Mpa between $Ni_{59}Cr_{24}$ alloy and vintage halo(H2 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 H2 specimens.

• 한국세라믹학회지
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• 제49권3호
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• pp.247-252
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• 2012

Crystal structure and chemical compositions of Plasma electrolytic oxidized layer of A-1100, A-2024, A-5052, A-6061, A-6063, A-7075, ACD-7B and ACD-12 were investigated. The electrolyte for plasma electrolytic oxidation was mixture of distilled water, $Na_2P_2O_7$, Cu, Cr metal salts and KOH. ${\eta}$-Alumina, as well as ${\alpha}$-alumina, was main crystal phase. Another crystals such as $(Al_{0.948}Cr_{0.052})_2O_3$ and $(Al_{0.9}Cr_{0.1})_2O_3$ were also formed in the oxide layer. It was thought that the effect of electrolyte compositions on the physical properties and crystal system of PEO layers was greater than the effect of Al alloy composition variation.

• 한국표면공학회지
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• 제47권1호
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• pp.13-19
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• 2014

The various surface treated conditions of Fe-3.0%Ni-0.7%Cr-1.4%Mn-X steel such as as-received, ion nitriding, DLC coated, DLC coated after nitriding for 3 hrs and 6 hrs were investigated to evaluate the beneficial effect for plastic mold steel. Micro Vickers hardness tester was used to estimate nitriding depth from the hardness profile and to measure hardness on the surface. Elastic modulus and residual stress were measured by a nanoindentator. Scratch test and SP (small ball punch test) were utilized to assess the adhesive strength of DLC coating. The depth of nitriding layer was measured as $50{\mu}m$ for the condition of 3 hrs nitriding and $90{\mu}m$ for that of 6 hrs nitriding. Hardness, elastic modulus, residual stress of DLC coating were 20.37 GPa, 162.78 GPa and -1456 MPa respectively. Residual stress on the surface of DLC coating after nitriding could increase to -3914 MPa by introducing nitriding before DLC coating. During the 'Ball-On-Disc' test ${\gamma}^{\prime}$ particles pulled out from the surface of nitrized layer tend to enhance abrasive wear mode since the fraction of ${\gamma}^{\prime}$ (Fe4N) in ion-nitrized layer is known to increases with nitriding time. Thus the specific wear rate of the nitriding layer increased. Comparing with nitriding the specific wear rate in work piece disc as well as ball decreased prominently in DLC coating due to the remarkable reduction in friction coefficient.

• 한국수소및신에너지학회논문집
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• 제21권3호
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• pp.201-206
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• 2010

In present work, $La_{0.8}Ca_{0.2}CrO_3$ (LCC) ceramic interconnect layer for SOFC was prepared by using thermal plasma spray coating process. The LCC powders were synthesized by Pechini method and calcined at the temperature of $1000^{\circ}C$. The prepared LCC powder was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), particle counter, BET analysis, respectively. In addition, basic and essential properties of LCC layer coated by thermal plasma spray coating process such as the morphology of surface and cross section for coated layer, gas leak rate, and electrical conductivity were analyzed and discussed. Based on these experimental results, it can be concluded that the LCC layer coated by thermal plasma spray coating process can be suitable as a ceramic interconnect of SOFC operated at $800^{\circ}C$.