http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 학과정보 : 금속공학(금속공학) Titanium alloy (검색결과 1 건)
-
열처리를 통한 Ti-6Al-4V 주조재 합금의 기계적 성질 개선
오성탁 전북대학교 일반대학원 2016 국내석사
Titanium alloys have been used in a number of parts as not only aerospace components but also marine and biomedical applications due to lightweight, high specific strength, and corrosion resistance. Particularly, Ti-6wt%Al-4wt%V alloy which is one of α+β titanium alloys has been utilized in the various applications due to its excellent combination of strength and ductility. In addition, Ti-6Al-4V alloy is heat-treatable to develop a variety of microstructure and mechanical property combinations. Thus, in wrought Ti-6Al-4V alloy, the improvement of their mechanical properties by a heat treatment has been studied for a long time. However, in cast Ti-6Al-4V alloy, it is still required to study on heat treatment process and strengthening mechanism to derive the increased strength and ductility of cast Ti-6Al-4V alloy. From the above viewpoint, in this study, the microstructure refinement which is one of the strengthening mechanisms is applied to improve the mechanical properties by the heat treatment on cast Ti-6Al-4V alloy. Additionally, the effect of the heat-treatment condition and stabilizer partitioning (Al,V) on the microstructure control and phase transformation of the β phase was investigated. Moreover, the further strengthening mechanism was investigated to obtain the improvement of the strength and ductility. The precipitation strengthening by α2 (Ti3Al) precipitates is well known in Ti-6Al-4V alloy to improve the further mechanical properties. However, it needs a long time to precipitate the α2 phase. To overcome this disadvantage, the short-time aging treatment was performed after the solution treatment in present study. With the relatively short aging time, the further strengthening mechanism of the retained β phase on microstructure and mechanical properties was investigated. From the results in present study, the microstructure of cast Ti-6Al-4V alloy was greatly refined through the solution and subsequent aging treatments due to α and β phases decomposed from α' martensite. As well as, the microstructure control was determined by the prior solution treatment. The solution heat-treated microstructure and phase transformation of the β phase was strongly dependent on the concentration of vanadium in the β phase in cast Ti-6Al-4V alloy. Furthermore, although the short-aging treatment for 5 minutes was conducted, its combination of tensile strength and elongation was further improved, relatively compared to that of aged specimen for 1440 minutes. Its effects and reasons were discussed in present study.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
