초록 ▼

1. 고강도 내마모 나노구조 서멧/세라믹 용사코팅 기술개발, 포항산업과학연구원, 황순영- 기존 나노구조 서멧분말 특성분석을 통한 개발 분말에 요구되는 특성 및 설계기준 제시 및 분말제조- HVOF, Cold spray 기술을 통한 초경코팅 미세조직 및 기계적 특성 $30\%$, 내마모성 $80\%$이상 향상- 공정변수 최적화 및 carbon 첨가, 초기분말의 코팅을 통한 코팅 내마모성 향상- 코팅 표면조도 측정결과 개발된 나노구조 초경 코팅의 가공특성 향상 및 산업현장 적용 위한 시제품 개발-

1. 고강도 내마모 나노구조 서멧/세라믹 용사코팅 기술개발, 포항산업과학연구원, 황순영- 기존 나노구조 서멧분말 특성분석을 통한 개발 분말에 요구되는 특성 및 설계기준 제시 및 분말제조- HVOF, Cold spray 기술을 통한 초경코팅 미세조직 및 기계적 특성 $30\%$, 내마모성 $80\%$이상 향상- 공정변수 최적화 및 carbon 첨가, 초기분말의 코팅을 통한 코팅 내마모성 향상- 코팅 표면조도 측정결과 개발된 나노구조 초경 코팅의 가공특성 향상 및 산업현장 적용 위한 시제품 개발- 기 개발 마이크론구조 고상윤활분말(PS304)의 플라즈마 코팅을 통한 미세조직 불균질성 확인- 코팅 성능 향상을 위해 경화상(Cr2O3)의 나노크기 첨가 및 분무건조 분말제조법을 통한 나노구조 분말 제조- 개발 분말의 플라즈마 용사코팅 특성평가 결과 기존 마이크론구조 ？A팅에 비해 미세조직의 균일성 및 기공율, 경도, 접합강도 등의 코팅 기계적 특성 1.5-2배 향상- 코팅 마모특성 향상을 위한 분말 최적화 열처리 조건 확립 및 성분 비 변경을 통한 내마모성 향상 (기존 코팅 마찰계수: $0.4\sim0.6(RT)$, 나노구조 코팅 마찰계수 : 0.2-0.4(RT))- 코팅실기테스트를 통한 산업현장적용 기준(10000cycle) 통과

Abstract ▼

This study is focused on two parts. The first one is a development of WC-based nano-sbuctured coatings and the other is a development of low-friction hard coatings for air foil bearings. These developments are initiated after survey of industrial needs.WC-based nano-sbuctured coatings are developed

This study is focused on two parts. The first one is a development of WC-based nano-sbuctured coatings and the other is a development of low-friction hard coatings for air foil bearings. These developments are initiated after survey of industrial needs.WC-based nano-sbuctured coatings are developed using a new technology for formation of nano-sbuctured feedstock and optimization of process variables of thermal spraying equipments. The new technology for the formation of the feedstock is called flocculation method. We use a flocculation of a few nano particles and secondary formation of flocculated particles. Using this technology, the control of porosity and shape of the feedstock powders. The process parameters are optimized using the Taguchi method. Also, two other methods are tried such as high carbon feed stock processing and cobalt coating of the feedstock to decrease decarburization. The wear rate is measured by a dry sand abrasion test. As results, increase of $80\%$ wear resistance is obtained.To increase the wear resistance further, heat treatment of the coating is tried. Using the Response Surface Method, the optimization of heat treatment conditions are developed and further increase of wear resistance up to $188\%$ increase of wear resistance.The second part of development is a low friction high temperature hard coating development. This was first developed as high temperature oilless coatings by NASA. They developed coatings for air foil bearings of turbo or gas turbine engines. They used plasma spray coating technique. The materials are composed of bonding materials (NiCr) +hard materials (Cr203) + solid lubricant materials (Ag and BaF2jCaF2).They used blended powders of each constituent.To increase the wear resistance and decrease the friction coefficient, nano-powders of Cr203 is tried to spray dry the powders. Using the patented special technology, spray dryed powders contained the four constituents uniformly in one powder. Using these special powders and optimization of plasma spraying parameters, decrease of a friction coefficient and a porosity level and increase of hardness and adhesion strength of the coatings is obtained The optimized coating is applied to Rig test components, and the coatings passed the first industrial criteria of the condition such as a 10,000 cycle test.