TY - JOUR
T1 - The use of various peening methods to improve the fatigue strength of titanium alloy Ti6Al4V manufactured by electron beam melting
AU - Soyama, Hitoshi
AU - Okura, Yuya
N1 - Funding Information:
This work was partly supported by JSPS KAKENHI Grant Number 17H03138. The authors wish to thank Mr. M. Mikami, Technician in the Department of Finemechanics, Tohoku University for his help in the experiments
Publisher Copyright:
© 2018, the Author(s).
PY - 2018
Y1 - 2018
N2 - Additive manufacturing (AM) of metals is one of the foremost methods used for making medical implants and components for aviation. However, the fatigue strength of AM metals is weaker than that of the bulk equivalent. Mechanically treating the surface, such as by shot peening, can improve the fatigue strength, and novel peening methods without shot have also been proposed. In this paper, in order to demonstrate the improvements made in AM metals by various peening methods, specimens made of titanium alloy Ti6Al4V manufactured by electron beam melting (EBM) were treated by shot peening, laser peening and cavitation peening, then assessed by a plate bending fatigue test. In the case of shot peening, the shots were accelerated by a water jet to mitigate the incidence of dust during the process. For laser peening, the specimen was placed in water, and the effect of the impact produced at the target due to collapsing bubbles, which developed after laser ablation of the surface, was greater than the effect due to the laser ablation itself. For cavitation peening, the cavitation was generated by injecting a high speed water jet into water. In each case improvements in the fatigue strength of the Ti6Al4V were made. Improvements of 104% by laser peening, 84% by cavitation peening and 68% by shot peening compared with a non-peened specimen were achieved.
AB - Additive manufacturing (AM) of metals is one of the foremost methods used for making medical implants and components for aviation. However, the fatigue strength of AM metals is weaker than that of the bulk equivalent. Mechanically treating the surface, such as by shot peening, can improve the fatigue strength, and novel peening methods without shot have also been proposed. In this paper, in order to demonstrate the improvements made in AM metals by various peening methods, specimens made of titanium alloy Ti6Al4V manufactured by electron beam melting (EBM) were treated by shot peening, laser peening and cavitation peening, then assessed by a plate bending fatigue test. In the case of shot peening, the shots were accelerated by a water jet to mitigate the incidence of dust during the process. For laser peening, the specimen was placed in water, and the effect of the impact produced at the target due to collapsing bubbles, which developed after laser ablation of the surface, was greater than the effect due to the laser ablation itself. For cavitation peening, the cavitation was generated by injecting a high speed water jet into water. In each case improvements in the fatigue strength of the Ti6Al4V were made. Improvements of 104% by laser peening, 84% by cavitation peening and 68% by shot peening compared with a non-peened specimen were achieved.
KW - Additive manufacturing
KW - Cavitation peening
KW - Electron beam melting
KW - Fatigue strength
KW - Laser peening
KW - Mechanical surface treatment
KW - Medical implant
KW - Shot peening
KW - Titanium alloy
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U2 - 10.3934/MATERSCI.2018.5.1000
DO - 10.3934/MATERSCI.2018.5.1000
M3 - Article
AN - SCOPUS:85062342343
VL - 5
SP - 1000
EP - 1015
JO - AIMS Materials Science
JF - AIMS Materials Science
SN - 2372-0484
IS - 5
ER -