Mechanical and Fatigue Characteristics of Ti–6Al–4V Extra Low Interstitial and Solution-Treated and Annealed Alloys After Ultrasonic Nanocrystal Surface Modification Treatment

Abstract

This study investigates the influence of ultrasonic nanocrystal surface modification (UNSM), a novel surface treatment technology, on the mechanical characteristics and rotary bending fatigue performance of solution-treated and annealed (STA) Ti-6Al-4V and Ti-6AI-4V extra low interstitial (ELI) alloys. Various techniques have been developed to use surface modification in order to improve fatigue performance of machine parts. The UNSM treatment emerges due to its ability to induce a distinctive combination of modifications in the top surface and the subsurface of the material. The mechanical properties are acquired and compared for UNSM-treated and untreated specimens. Fatigue data is acquired and compared for UNSM-treated and untreated specimens of Ti-6Al-4V ELI alloy by subjecting specimens to rotary-bending fatigue tests. Fracture analysis of failed specimens is performed. The improvement in the fatigue performance is observed for UNSM treated specimens. This improvement is attributed mainly to the UNSM-induced combination of following modifications: compressive residual stress, micro-hardness, and nanograin in the subsurface of the material.

Improving the Surface Integrity and Tribological Behavior of a High-Temperature Friction Surface via the Synergy of Laser Cladding and Ultrasonic Burnishing

“…It is known that tensile stress could facilitate crack initiation and propagation [30,31], and thus harm the mechanical property of the material. Compressive residual stress introduction is a key process effect of UB [32]. According to the results, the UB-treated coating had a compressive stress of about 322.45 MPa.…”

“…By combining Figures 6 and 7, it can be found that the residual stress measurements agree well with the diffraction peak shift. Compressive residual stress introduction is a key process effect of UB [32]. According to the results, the UB-treated coating had a compressive stress of about 322.45 MPa.…”

Influence of High-Intensity Zr Ion-Beam Treatment on Deformation and Fracture of 12Cr1MoV Steel under Static, Cyclic and Dynamic Loadings

“…One of the most important problems in engineering is to develop ways to extend the life-time of machine parts. An effective method to improve mechanical properties as well as to protect materials is coating deposition and surface layer modification [1][2][3]. Ion treatment has long time been used to modify the surface layer and to obtain their new structural phase states, which cannot be synthesized by means of traditional metallurgical melting process [4,5].…”