초록 ▼

차세대 가스터빈용 초고온 소재개발을 위한 1단계(3년) 1차년도 연구수행을 통하여, 진공중 서스펜션 플라즈마 스프레이 기술을 통한 열차폐코팅의 나노~마이크로 멀티사이즈 기공 분포 미세구조 구현, 0.8 W/mK의 저열전도(현행 기술 APS YSZ 1.2 W/mK) 확보하였으며, 현행 기술 APS YSZ대비 우수한 고온 내구성을 확인하였음. SiC_f/SiC CMC의 경우 고온특성 향상 및 공정시간 단축을 위한 고성능 SiC filler를 개발하였음. 기존에 제안된 passive filler 및 active fill

차세대 가스터빈용 초고온 소재개발을 위한 1단계(3년) 1차년도 연구수행을 통하여, 진공중 서스펜션 플라즈마 스프레이 기술을 통한 열차폐코팅의 나노~마이크로 멀티사이즈 기공 분포 미세구조 구현, 0.8 W/mK의 저열전도(현행 기술 APS YSZ 1.2 W/mK) 확보하였으며, 현행 기술 APS YSZ대비 우수한 고온 내구성을 확인하였음. SiC_f/SiC CMC의 경우 고온특성 향상 및 공정시간 단축을 위한 고성능 SiC filler를 개발하였음. 기존에 제안된 passive filler 및 active filler 외에 semi-active filler 라는 새로운 개념을 제안하였으며 Si-Al-C 및 Si-Ti-C에 대한 합성 및 조성, 특성 분석을 진행하였음. 65vol% 이상의 초고농도 나노 SiC 슬러리 제조 및 슬러리의 섬유 내 함침공정 개발을 진행하였음. 인공신경망(Neural network) 기법과 열역학 계산을 활용하여 크리프 특성이 우수한 Re-free 단결정 합금을 설계하였음. 상용소재인 CMSX-4 대비 약 70% 수준의 크리프 특성을 나타내었음. 합금원소가 상용 본드코팅층과 기지 사이 계면에 미치는 영향을 분석하여 Re의 증가로 TCP상과 SRZ 두께가 증가하는 것과 Ta 감소에 따른 TCP 상분율 감소, 그리고 W 증가에 따른 TCP상 감소를 알 수 있었음.

(출처 : 초록 3p)

Abstract ▼

The main objective of the project is to develop high temperature materials, including thermal barrier coating (TBC), SiC_f/SiC CMC and Re-free single crystal superalloy, for the next generation gas turbines. In the 1^st year of the project, ceramic top coating of TBC with the mul

The main objective of the project is to develop high temperature materials, including thermal barrier coating (TBC), SiC_f/SiC CMC and Re-free single crystal superalloy, for the next generation gas turbines. In the 1^st year of the project, ceramic top coating of TBC with the multi-scale pores in the range from nano to micro order was successfully fabricated using suspension vacuum plasma spray(SVPS), which is unconfirmed process technology worldwide.
This TBCs showed the low thermal conductivity of ~ 0.8 W/mK. It can be resulted by the distribution of the multi-scale pore in the ceramic coating. In the comparison of the thermal life of TBC preprepared by APS and SVPS, SVPS TBCs showed good thermal life.

In the case of SiC_f/SiC CMC, the weak point of LSI (Liquid Silicon Infiltration) process, which is currently commercialized, should be improved and the processing time and price should decrease. For that purpose, PIP (precursor Impregnation & pyrolysis) process, which is the second generation process) was developed. Development of SiC filler and highly concentrated slurry up to 65vol% were performed and the infiltration process of the slurry into fiber fabrics was investigated in order to improve high temperature properties and to decrease the processing time. As a result, 4 SCI papers were submitted and both domestic and international patents are in preparation. The developed technologies will be transferred to CMC fabrication companies, through which the 2^nd generation CMC fabrication technology can be used by the end-users.

One of aim in this study is to develop a new Re-free single crystal superalloy with high temperature properties equivalent to commercial alloy CMSX-4 with 3% of Re. The effects of alloying elements on various properties of single crystal alloys were investigated by thermodynamic calculation. Neural network modeling was also used to derive the compositions of alloys with good creep properties. The compositions derived by NN were filtered by thermodynamic calculation. On the basis of the calculation, chemical compositions of the 1st candidate alloys were suggested. After various trials, heat treatment conditions for candidate alloys to obtain optimum microstructure were decided. Creep tests of developed alloys after heat treatment were conducted and then the results were compared with that of commercial superalloy. Creep lives of the designed alloy is about 70% of those of commercial alloy, CMSX-4. Modification of compositions will enhance the properties of these alloys, which should be studied in the next year. The effect of alloying elements on interfacial reaction between base material and MCrAlY bond coats was also studied. The effect of Mo was not so significant, but increase of Re enhances the SRZ (Secondary Reacted Zone) and TCP(Topologically Closed Packed) phase formation on the interface between single crystal and bond coat. W reduced TCP phase formation unlike expectation.

(출처 : SUMMARY 5p)

목차 Contents

• 표지 ... 1
• 제 출 문 ... 2
• 보고서 초록 ... 3
• 요 약 문 ... 4
• SUMMARY ... 5
• CONTENTS ... 6
• 목차 ... 7
• 제 1 장 연구개발과제의 개요 ... 8
• 제 1 절 연구개발의 목적 ... 8
• 제 2 절 연구개발의 필요성 ... 8
• 제 2 장 국내외 기술개발 현황 ... 10
• 제 1 절 기술개발 동향 ... 10
• 제 2 절 특허 동향 ... 12
• 제 3 절 산업동향 ... 14
• 제 3 장 연구개발수행 내용 및 결과 ... 17
• 제 1 절 초고온 환경용 low-k TBC ... 17
• 제 2 절 2세대 SiCf/SiC CMC 공정 개발 ... 24
• 제 3 절 Re-free 단결정 초내열합금 개발 ... 32
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 41
• 제 1 절 목표 달성도 ... 41
• 제 2 절 관련 분야에의 기대효과 ... 43
• 제 5 장 연구개발결과의 활용계획 ... 44
• 제 1 절 연구 결과 활용 계획 ... 44
• 제 2 절 차년도 계획 ... 44
• 끝페이지 ... 46