초록 ▼

III. 연구개발의 내용 및 범위
◦ 비행체 엔진 소재용 개발합금의 조성범위를 선정
◦ 개발합금과 상용합금의 크리프 및 TMF 특성을 평가하여 상용합금과 비교
◦ 합금 우수성을 확인 및 합금 조성범위 및 최적의 기계적 특성을 갖는 합금 조성을 선정.
◦ 상용공정 적용 후 특성을 평가하고 열처리 조건 확립 및 상 안정성 평가도 수행.
◦ 판재 적용부품용 고강도, 고성형성 Ti합금설계 완성
▪ 여타 Ti합금 및 Ti-6Al-4Fe-xSi계 합금에 대한 β변태점 및 유동응력계산과 비교분석
▪

III. 연구개발의 내용 및 범위
◦ 비행체 엔진 소재용 개발합금의 조성범위를 선정
◦ 개발합금과 상용합금의 크리프 및 TMF 특성을 평가하여 상용합금과 비교
◦ 합금 우수성을 확인 및 합금 조성범위 및 최적의 기계적 특성을 갖는 합금 조성을 선정.
◦ 상용공정 적용 후 특성을 평가하고 열처리 조건 확립 및 상 안정성 평가도 수행.
◦ 판재 적용부품용 고강도, 고성형성 Ti합금설계 완성
▪ 여타 Ti합금 및 Ti-6Al-4Fe-xSi계 합금에 대한 β변태점 및 유동응력계산과 비교분석
▪ 합금설계 방법론 구축 및 Ti합금설계안 도출
▪ ISM용해 설비를 이용한 용해설계 및 합금원소 장입 및 조건 도출
◦ 개량 설계된 고성형성 Ti합금 후보소재 sample 제조 및 최종 Ti합금 선정
▪ Ti-6Al-4Fe (base metal) 및 Ti-6Al-4Fe-0.1, 0.25Si합금의 ISM용해 및 sample제조
▪ 변형공정지도를 활용한 잉고트 파쇄공정 및 압연공정조건 도출
▪ Ti-6Al-4Fe (base metal) 및 Ti-6Al-4Fe-0.1, 0.25Si합금의 2mm Ti합금 시험용 판재제조
▪ 제조된 2mm Ti합금 시험용 판재와 상용 Ti-6Al-4V 및 Ti-3Al-2.5V합금 판재간 조직, 경도, V자 굽힘, 초소성(700℃, 저속 인장시험)시험 및 특성비교

Abstract ▼

Two strategic metallic materials have been investigate for weapons systems to enhance the performance and the efficiency. In order to enhance the efficiency of aero-engines, increasing turbine inlet temperature (TIT) and application high performance alloys for the components are inevitable. Creep an

Two strategic metallic materials have been investigate for weapons systems to enhance the performance and the efficiency. In order to enhance the efficiency of aero-engines, increasing turbine inlet temperature (TIT) and application high performance alloys for the components are inevitable. Creep and thermo-mechanical fatigue (TMF) tests of the developed alloys and CMSX-4 have been conducted. The dislocation structure after creep and TMF tests were observed to investigate the deformation mechanism. Creep tests after commercial coating on the specimen were conducted to see applicability of commercial process to the developed alloy.
The developed alloy has superior creep properties and TMF properties to the commercial second generation single crystal superalloy, CMSX-4. The dislocation structure after creep and TMF were observed to discuss difference of the alloys in deformation mechanism. The creep properties of developed alloy after commercial coating were reduced. New coating materials should be investigated. Optimum heat treatment prodedure has been also developed. A model blade which is really used in aero engine will be cast with the developed alloy to explore the application of the new alloy.
Alloy design of new titanium alloy with high strength and formability was investigated by the computational method and experimental analysis. The target of alloy design is a grain refinement, beta transus temperature reduction, and flow stress reduction at the forming temperature region. Initially, the effect of Si element on the strength and formability of base titanium alloy was analyzed with computational method and microstructural observation of induction skull melted titanium alloy samples(Ti-6Al-4Fe, Ti-6Al-4Fe-0.1Si and Ti-6Al-4Fe-0.25Si). In order to determine the hot forging and rolling conditions, deformation process map was generated using the dynamic materials model(DMM) and hot compression tests data. The developed titanium alloy sheets were manufactured with hot forming conditions obtained from the deformation process map.
The strength and formability of designed titanium alloy sheets were evaluated by bending and tensile tests at room temperature and 700℃. In banding test, a commercial Ti-6Al-4Fe sheet showed the cracking. On the other hand, the developed titanium alloy sheets were bended without the cracking. In tensile test at room temperature, the strength of developed titanium alloy sheets indicated higher than that of a commercial Ti-6Al-4V alloy. Whereas, flow stress level at the forming temperature range of the developed titanium alloy is smaller than that of Ti-6Al-4V alloy.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 보고서 초록 ... 3
• 요약문 ... 4
• SUMMARY ... 6
• CONTENTS ... 7
• 목 차 ... 8
• 제1장 연구개발과제의 개요 ... 9
• 제2장 국내외 기술개발 현황 ... 10
• 제3장 연구개발수행 내용 및 결과 ... 12
• 제1절 비행체 엔진소재 개발 ... 12
• 제2절 고성형성 Ti합금 판재 및 응용부품 제조기술 개발 ... 21
• 제4장 목표달성도 및 관련분야에의 기여도 ... 32
• 제5장 연구개발결과의 활용계획 ... 33