MSA  Vol.7 No.4 , April 2016
Using Cavitation Peening to Improve the Fatigue Life of Titanium Alloy Ti-6Al-4V Manufactured by Electron Beam Melting
Abstract: Although Electron Beam Melting (EBM) is an innovative technology, the fatigue properties of materials manufactured by EBM may be lower than those of casted and wrought materials due to defects and surface roughness. In order to enhance the fatigue life of components or structures manufactured by EBM, a mechanical surface treatment technology, e.g., peening, would be effective because peening introduces high compressive residual stress at the surface which can extend the fatigue life considerably. In the present study, specimens were manufactured by EBM using titanium alloy Ti-6Al-4V powder. Two types of specimens were prepared: as-built and as-machined specimens. Specimens of each type were treated by cavitation peening or shot peening. The fatigue lives of the specimens were evaluated by a plate bending fatigue tester. The residual stress and surface roughness were also evaluated. The results obtained showed that the fatigue strength of as-built specimens can be improved by 21% by cavitation peening or shot peening, and the fatigue life under particular applied stresses can also be extended by 178% by cavitation peening.
Cite this paper: Sato, M. , Takakuwa, O. , Nakai, M. , Niinomi, M. , Takeo, F. and Soyama, H. (2016) Using Cavitation Peening to Improve the Fatigue Life of Titanium Alloy Ti-6Al-4V Manufactured by Electron Beam Melting. Materials Sciences and Applications, 7, 181-191. doi: 10.4236/msa.2016.74018.

[1]   Edwards, P., O’Conner, A. and Ramulu, M. (2013) Electron Beam Additive Manufacturing of Titanium Components: Properties and Performance. Journal of Manufacturing Science and Engineering, 135, 061016.

[2]   Brandl, E., Baufeld, B., Leyens, C. and Gault, R. (2010) Additive Manufactured Ti-6Al-4V Using Welding Wire: Comparison of Laser and Arc Beam Deposition and Evaluation with Respect to Aerospace Material Specifications. Physics Procedia, 5, 595-606.

[3]   Baufeld, B., Van der Biest, O. and Gault, R. (2010) Additive Manufacturing of Ti-6Al-4V Components by Shaped Metal Deposition: Microstructure and Mechanical Properties. Material and Design, 31, S106-S111.

[4]   Wycisk, E., Solbanch, A., Siddique, S., Herzog, D., Walther, F. and Emmelmann, C. (2014) Effects of Defects in Laser Additive Manufactured Ti-6Al-4V on Fatigue Properties. Physics Procedia, 56, 371-378.

[5]   Baufeld, B. and Van der Biest, O. (2009) Mechanical Properties of Ti-6Al-4V Specimens Produced by Shaped Metal Deposition. Science and Technology of Advanced Materials, 10, 015008.

[6]   Champoux, R.L., Underwood, J.H. and Kapp, J.A. (1988) Analytical and Experimental Methods for Residual Stress Effects in Fatigue. American Society for Testing and Materials Special Technical Publication STP 1004.

[7]   Takakuwa, O., Yamamiya, K. and Soyama, H. (2012) An Indicator for the Suppression of Fatigue Crack Growth by Hybrid Peening. Journal of Solid Mechanics and Materials Engineering, 3, 357-371.

[8]   Takakuwa, O. and Soyama, H. (2015) Effect of Residual Stress on the Corrosion Behavior of Austenitic Stainless Steel. Advances in Chemical Engineering and Science, 5, 62-71.

[9]   Wang, S.P., Li, Y.J., Yao, M. and Wang, R.Z. (1998) Compressive Residual Stress Introduced by Shot Peening. Journal of Materials Processing Technology, 73, 64-73.

[10]   Soyama, H., Saito, K. and Saka, M. (2002) Improvement of Fatigue Strength of Aluminum Alloy by Cavitation Shotless Peening. Journal of Engineering Materials and Technology, 124, 135-139.

[11]   Soyama, H. (2011) Enhancing the Aggressive Intensity of a Cavitating Jet by Means of the Nozzle Outlet Geometry. Journal of Fluids Engineering, 133, 101301.

[12]   Soyama, H., Macodiyo, D.O. and Mall, S. (2004) Compressive Residual Stress into Titanium Alloy Using Cavitation Shotless Peening Method. Tribology Letters, 17, 501-504.

[13]   Soyama, H. (2014) The Use of Cavitation Peening to Increase the Fatigue Strength of Duralumin Plates Containing Fastener Holes. Materials Sciences and Applications, 5, 430-440.

[14]   Soyama, H. and Sekine, Y. (2010) Sustainable Surface Modification Using Cavitation Impact for Enhancing Fatigue Strength Demonstrated by a Power Circulating-Type Gear Tester. International Journal of Sustainable Engineering, 3, 25-32.

[15]   Soyama, H., Shimizu, M., Hattori, Y. and Nagasawa, Y. (2008) Improving the Fatigue Strength of the Elements of a Steel Belt for CVT by Cavitation Peening. Journal of Materials Science, 43, 5028-5030.

[16]   Soyama, H. (2014) Enhancing the Aggressive Intensity of a Cavitating Jet by Introducing a Cavitator and a Guide Pipe. Journal of Fluid Science and Technology, 9, JFST0001-1-12.

[17]   Soyama, H. (2011) Corrosion Behavior of Pressure Vessel Steel Exposed to Residual Bubbles after Cavitation Bubble Collapse. Corrosion, 67, 025001-1-025001-8.

[18]   Naito, A., Takakuwa, O. and Soyama, H. (2012) Development of Peening Technique Using Recirculating Shot Accelerated by Water Jet. Material Science and Technology, 28, 234-239.

[19]   Soyama, H. (2007) Improvement of Fatigue Strength by Using Cavitating Jets in Air and Water. Journal of Materials Science, 42, 6638-6641.

[20]   Takakuwa, O. and Soyama, H. (2013) Optimizing the Conditions for Residual Stress Measurement Using a Two-Di- mensional XRD Method with Specimen Oscillation. Advances in Materials Physics and Chemistry, 3, 8-18.

[21]   Little, R.E. (1972) Estimating the Median Fatigue Limit for Very Small Up-and-Down Quantal Response Tests and for S-N Data with Runouts. American Society for Testing and Materials Special Technical Publication STP511, 29-42.

[22]   Kanou, S., Takakuwa, O., Mannava, S.R., Qian, D., Vasudevan, V.K. and Soyama, H. (2012) Effect of the Impact Energy of Various Peening Techniques on the Induced Plastic Deformation Region. Journal of Materials Processing Technology, 212, 1998-2006.

[23]   Takakuwa, O., Gill, A.S., Ramakrishnan, G., Mannava, S.R., Vasudevan, V.K. and Soyama, H. (2013) Introduction of Compressive Residual Stress by Means of Cavitation Peening into a Titanium Alloy Rod Used for Spinal Implants. Materials Sciences and Applications, 4, 23-28.

[24]   Soyama, H. and Yamada, N. (2008) Relieving Micro-Strain by Introducing Macro-Strain in a Polycrystalline Metal Surface by Cavitation Shotless Peening. Materials Letters, 62, 3564-3566.

[25]   Maiya, P.S. and Busch, D.E. (1975) Effect of Surface Roughness on Low-Cycle Fatigue Behavior of Type 304 Stainless Steel. Metallurgical Transactions A, 6, 1761-1766.

[26]   Takakuwa, O. and Soyama. (2014) Application of Re-circulating Shot Peening Method Using a Water Jet to Spinal Implant Rod. Journal of Jet Flow Engineering, 31, 20-27 (in Japanese).

[27]   Beghini, M. and Bertini, L. (1990) Fatigue Crack Propagation through Residual Stress Field with Closure Phenomena. Engineering Fracture Mechanics, 36, 379-387.

[28]   Knowles, D.M., Downes, T.J. and King, J.E. (1993) Crack Closure and Residual Stress Effects in Fatigue of a Particle- Reinforced Metal Matrix Composite. Acta Metallurgica et Materialia, 41, 1189-1196.

[29]   Lads, D.A., Apelian, D. and Donald, J.K. (2007) Fracture Mechanics Analysis for Residual Stress and Crack Closure Corrections. International Journal of Fatigue, 29, 687-694.