Electrically Assisted Ultrasonic Nanocrystal Surface Modification of Ti6Al4V Alloy. Issue 1 (31st August 2017)

• Record Type: Journal Article
• Authors: Liu, Jun; Suslov, Sergey; Li, Shengxi; Qin, Haifeng; Ren, Zhencheng; Doll, Gary L.; Cong, Hongbo; Dong, Yalin; Ye, Chang
• Is Part Of: Advanced engineering materials. Volume 20:Issue 1(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-31
• Subjects: Ultrasonic nanocrystal surface modification -- electrically assisted deformation -- severe plastic deformation -- nanocrystalline -- dynamic precipitation; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201700470
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : In this study, an innovative process, electrically assisted ultrasonic nanocrystal surface modification (EA‐UNSM), is used to process Ti6Al4V alloy. As compared with traditional UNSM, EA‐UNSM results in lower dislocation density and larger grains due to the thermal annealing effect caused by resistive heating. In addition, deeper plastic deformation layer is observed in the electrically assisted case. By supplying mechanical energy and thermal energy simultaneously, a strong dynamic precipitation effect is induced, which generates nanoscale precipitates in the EA‐UNSM‐treated Ti6Al4V alloy. These nanoscale precipitates can effectively pin dislocations during plastic deformation and thus significantly improve the surface hardness. Abstract : Electrically assisted UNSM (EA‐UNSM) takes advantages of high strain rate plastic deformation and dynamic precipitation, producing a unique structure with nanoscale grains and non‐uniformly distributed nano‐precipitates. It is observed that the pinning effect exerted by the nanoscale precipitates lead to stronger surfaces, though thermal annealing effect results in grain growth during EA‐UNSM.