Ti-6Al-4V재의 UNSM처리에 의한 회전굽힘피로특성변화
Variation of Rotating Bending Fatigue Characteristics by UNSM on Ti-6Al-4V
0
조회
0
다운로드
4
인용
0
참고문헌
키워드
초록
In order to analyze feasibility of replacing a conventional 6-mm Ti bar with a 5-mm bar, a series of rotating bending fatigue tests were carried out on Ti-6Al-4V bars by strengthening the fatigue performance using a special technique called UNSM (Ultrasonic Nanocrystal Surface Modification). The results of S-N curves clearly showed that the performance of the 5-mm titanium specimen was similar to that of the 6-mm specimen when the UNSM treatment was applied. The 5-mm treated specimen converged with small scattering band into the linear line of the non-treated 6-mm one. Below the fatigue life of 10^5 cycles, the UNSM treatment did not show any significant superiority in the bending stress and fatigue life. However, over the fatigue life of 10^5 cycles, the effect of UNSM was superior for each fatigue life, and the bending stress became longer and higher than that of the untreated one. In the case of 6-mm Ti-bar with UNSM, the fatigue limit was about 592 MPa, and there was fatigue strength increase of about 30.7% at the fatigue life of 104 cycles compared to the untreated 6-mm bar. Therefore, the compressive residual stress made by the UNSM in Ti-6Al-4V increased the fatigue strength by more than 30%
Abstract
In order to analyze feasibility of replacing a conventional 6-mm Ti bar with a 5-mm bar, a series of rotating bending fatigue tests were carried out on Ti-6Al-4V bars by strengthening the fatigue performance using a special technique called UNSM (Ultrasonic Nanocrystal Surface Modification). The results of S-N curves clearly showed that the performance of the 5-mm titanium specimen was similar to that of the 6-mm specimen when the UNSM treatment was applied. The 5-mm treated specimen converged with small scattering band into the linear line of the non-treated 6-mm one. Below the fatigue life of 10^5 cycles, the UNSM treatment did not show any significant superiority in the bending stress and fatigue life. However, over the fatigue life of 10^5 cycles, the effect of UNSM was superior for each fatigue life, and the bending stress became longer and higher than that of the untreated one. In the case of 6-mm Ti-bar with UNSM, the fatigue limit was about 592 MPa, and there was fatigue strength increase of about 30.7% at the fatigue life of 104 cycles compared to the untreated 6-mm bar. Therefore, the compressive residual stress made by the UNSM in Ti-6Al-4V increased the fatigue strength by more than 30%
참고문헌 (14)
- Altenberger, I, "Deep Rolling - The Past, The Present and The Future", Proc. 9th Int. Conf. on Shot Peening, pp.144~155 (2005)
- Chai,G, "The Formation of Subsurface Non-Defect Fatigue Crack Origins", International Journal of Fatigue, 28(11), pp.1533~1539 (2006)
- Ochi, Y, "Effects of Laser Peening Treatment Without Protective Coation on High Cycle Fatigue Property of Ti-6Al-4V alloy", 5th International conference on Very High Cycle Fatigue, pp.369~374 (2011)
- Petit, J, "Very High Cycle Fatigue Behavior of Ti6246 Alloy in Air and in High Vacuum", 4th International Conference on Very High Cycle Fatigue, pp.399~408 (2007)
- Prevey, P, "Overview of Low Plasticity Burnishing for Mitigation of Fatigue Damage Mechanisms", Proc. 9th Int. Conf. on Shot Peening, pp.267~272 (2005)
- Suh, C.M, "Improvement of VHCF Properties of AISI 1045, 4137, 52100 & H13 steel by UNSM treatment", 2011년도 한국해양과학기술협의회 공동학술대회, pp.1574~1579 (2011)
- Suh, C.M., "A Stduy on The Alternative Technonogy Using UNSM Instead of The Persetting Method for Torsion Bar", International journal of modern physics B, 24(15-16), pp.2435~2440 (2010)
- Suh, C.M, "Fatigue Microcracks in a Low Carbon Steel", Fatigue Fract. Engng. Mater. Struct, 8(2), pp.193~203 (1985)
- Suh, C.M, "Crack Growth Behaviour of Fatigue Microcracks in Low Carbon Steels", Fatigue Fract. Engng. Mater. Struct, 9(6), pp.409~424 (1987)
- 서창민, "Fatigue characteristics of bearing steel in very high cycle fatigue", Journal of Mechanical Science and Technology, 23(2), pp.420~425 (2009), 대한기계학회
- Suh, C.M, "Fatigue and mechanical characteristics of nano-structured tool steel by ultrasonic cold forging technology", MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 443(1-2), pp.101~106 (2007), ELSEVIER SCIENCE SA
- High Cycles Fatigue (HCF) Science and Technology Program 2001 Annual Report, "Thomas, M.B", ~, pp.AFRL-PR-WPTR- 2002-2060 (2002)
- Watanabe, Y, "Effect of Ultrasonic Shot Peening on Fatigue Strength of High Strength Steel", Proc. 8th Int. Conf. on Shot Peening, pp.306~310 (2003)
- 편영식, "초음파 나노표면개질기술의 특성과 활용방안 연구", 대한기계학회논문집 A, 33(03), pp.190~195 (2009), 대한기계학회