Hostname: page-component-848d4c4894-2pzkn Total loading time: 0 Render date: 2024-05-25T20:54:32.868Z Has data issue: false hasContentIssue false

Surface integrity generated with peripheral milling and the effect on low-cycle fatigue performance of aeronautic titanium alloy Ti-6Al-4V

Published online by Cambridge University Press:  13 December 2017

D. Yang
Affiliation:
School of Mechanical Engineering, Shandong University, Jinan, China Department of Mechanical Engineering, Anhui University, Hefei, China
Z. Liu*
Affiliation:
School of Mechanical Engineering, Shandong University, Jinan, China

Abstract

Machining-induced surface integrity has an important effect on reliability and service life of the components used in the aerospace industry where titanium alloy Ti-6Al-4V is widely applied. Characterisation of machining-induced surface integrity and revealing its effect on fatigue life are conducive to structural fatigue life optimisation design. In the present study, surface topography, residual stress, microstructure and micro-hardness were first characterised in peripheral milling of titanium alloy Ti-6Al-4V. Then, low-cycle fatigue performances of machined specimens were investigated on the basis of the tension-tension tests. Finally, the effects of surface integrity factors (stress concentration factor, residual stress and micro-hardness) on fatigue performances were discussed. Results show that stress concentration can reduce the fatigue life while increasing the residual compressive stress, and micro-hardness is beneficial to prolonging the fatigue life, but when the surface material of the specimen is subjected to plastic deformation due to yield, the residual stress on the surface is relaxed, and the effect on the fatigue performance is disappeared. Under the condition of residual stress relaxation, the stress concentration factor is the main factor to determine the low-cycle fatigue life of titanium alloy Ti-6Al-4V. While for the specimens with no residual stress relaxation, micro-hardness was the key factor to affect the fatigue life, followed by residual stress and stress concentration factor, respectively.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Cheng, Z. and Liao, R. Effect of surface topography on stress concentration factor, Chinese J Mechanical Engineering, 2015, 28, (6), pp 1141-1148.Google Scholar
2. Wang, Y., Meletis, E. I. and Huang, H. Quantitative study of surface roughness evolution during low-cycle fatigue of 316L stainless steel using scanning whitelight interferometric (SWLI) Microscopy, Int J Fatigue, 2013, 48, pp 280-288.Google Scholar
3. Peterson, R. E. Stress Concentration Factors, 1974, John Wiley and Sons, New York, New York, US.Google Scholar
4. Arola, D. and Ramulu, M. An examination of the effects from surface texture on the strength of fiber-reinforced plastics, J Composite Materials, 1999, 33, (2), pp 101-186.Google Scholar
5. Yao, C. F., Wu, D. X. and Jin, Q. C. Influence of high-speed milling parameter on 3D surface topography and fatigue behavior of TB6 titanium alloy, Transactions of Nonferrous Metals Society of China, 2013, 23, (3), pp 650-660.Google Scholar
6. Yakovlev, M. G. Improving fatigue strength by producing residual stresses on surface of parts of gas-turbine engines using processing treatments, J Machinery Manufacture and Reliability, 2014, 43, (4), pp 283-286.Google Scholar
7. Zlatin, N. and Field, M. Procedures and precautions in machining titanium alloys, Titanium Science and Technology, 1973, Springer US, Boston, pp 489-504.Google Scholar
8. Sridhar, B. R., Devananda, G. and Ramachandra, K. et al. Effect of machining parameters and heat treatment on the residual stress distribution in titanium alloy IMI-834, J Materials Processing Technology, 2003, 139, pp 628-634.Google Scholar
9. Guerville, L., Vigneau, J. and Dudzinski, D. Influence of machining conditions on residual stresses, Metal Cutting and High Speed Machining, 2002, Kluwer Academic Plenum Publishers, Netherlands, pp 201-210.Google Scholar
10. Leyens, C. and Peters, M. Titanium and Titanium Alloys, Wiley-VCH, Weinheim, 2003.Google Scholar
11. Sealy, M. P., Guo, Y. B. and Caslaru, R. C. et al. Fatigue performance of biodegradable magnesium–calcium alloy processed by laser shock peening for orthopedic implants, Int J Fatigue, 2016, 82, pp 428-436.CrossRefGoogle Scholar
12. Sasahara, H. The effect on fatigue life of residual stress and surface hardness resulting from different cutting conditions of 0.45% C steel, Int J Machine Tools and Manufacture, 2005, 45, (2), pp 131-136.Google Scholar
13. Wu, G. Q., Shi, C. L. and Sha, W. et al. Effect of microstructure on the fatigue properties of Ti–6Al–4V titanium alloys, Materials & Design, 2013, 46, pp 668-674.Google Scholar
14. Polasik, A. The Role of Microstructure on High Cycle Fatigue Lifetime Variability in Ti-6Al-4V, Diss. The Ohio State University, 2014.Google Scholar
15. ASTM E915-10, Standard test method for verifying the alignment of x-ray diffraction instrumentation for residual stress measurement, ASTM, 2010.Google Scholar
16. Sunder, R. Why and how residual stress affects metal fatigue, Advanced Materials, 2016, Springer International Publishing, pp 489-504.Google Scholar