The Structure and Mechanical Properties of VT23 Welded Joints with Surface Layer Modified by Ultrasonic Mechanical Forging

Abstract:

The structure and mechanical properties of welded joints of VT23 titanium alloy received by method of laser welding after modifying the surface layers by ultrasonic mechanical forging (Treatment 1 and Treatment 2) were investigated. The experimental tests have revealed that the Treatment 2 provides a multiple increase in the relaxation property in fatigue life test. The formation of nonuniform distribution of vanadium, chromium and molybdenum in the welded joint increases the strength and, at the same time, the brittleness of β-phase. Mechanical treatment of the surface layers in the second mode provides a multiple increase in ductility up to 13%, in the as-received condition up to 9.9%. In consequence of plastic deformation, the β-phase intensity reduces twice with Treatment 2 which is related to its clustering. As follows from a presented data, the fatigue life of the VT23 titanium alloy has increased more than threefold.

• Periodical: Key Engineering Materials (Volume 743)
• Pages: 264-268
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.743.264
• Online since: July 2017
• Authors: Anastasia Smirnova*, Yury Pochivalov, Victor Panin, Anatoly Orishich, Aleksandr G. Malikov, Vasily Fomin, Anton Gorbunov
• Keywords: Crystals Twin, Nanostructural State, Titanium Alloys VT23, Ultrasonic Mechanical Forging, Welded Joints

References

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DOI: 10.1134/s1029959915020010

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