Enhanced fatigue properties of Ti-6Al-4V alloy turbine blades via formation of ultra-fine grained structure and ion implantation of surface

Abstract

Abstract. An overall approach to enhance service properties of Ti alloys is based on material nanostructuring in its volume and surface layer. In this work ultrafine-grained (UFG) structure is formed in Ti-6Al-4V alloy through equal channel angular pressing via the Conform scheme with subsequent drawing. Samples modelling the shape of blades are prepared. Their surface is subjected to ion implantation with N + . Fatigue tests are performed in the conditions imitating the stress-strain state of blades. It is shown the increasing the resistance of a high-cycle fatigue of blades due to formation of the UFG structure and subsequent surface modification in the material. The fatigue behaviour of the UFG alloy subjected to ion implantation is discussed.

Enhanced Creep Resistance of an Ultrafine‐Grained Ti–6Al–4V Alloy with Modified Surface by Ion Implantation and (Ti + V)N Coating

“…Processing details are described in the previous work. [25] The physical vapor deposition (PVD) coating of (Ti þ V)N was applied on the cylindrical samples in a vacuum plant WATT-900-3D. [24] The PVD coating consisted of two alternating intermediate Ti layers and two main layers of (Ti þ V)N with a total thickness of %5 μm.…”

“…Each sample surface was subjected to an EPT, a subsequent ion implantation (designated as ii) with nitrogen N + . Processing details are described in the previous work . The physical vapor deposition (PVD) coating of (Ti + V)N was applied on the cylindrical samples in a vacuum plant WATT‐900‐3D .…”

“…Usually, at ion implantation the penetration depth of nitrogen in the surface of the TiÀ6AlÀ4V alloy does not exceed %6 μm. [25] The microstructure and chemical composition of the coating were described in an earlier report. [24] 2.2.…”

“…To estimate the creep resistance of UFG samples with and without coating, Figure 5 shows a summary of the typical creep Figure 4. The 100 h creep rupture strength of TiÀ6AlÀ4V in the CG and UFG states [25] and UFG with i.i. þ coating.…”

Mechanical and structural behaviour of TiAlV nanocrystalline elaborated by mechanical milling technique

“…One of the largest users of these alloys is the aerospace area due to their specific strength ratio and a good balance of its properties. It is used as a material in compressor discs, airframe structure, satellites, and space rockets [22–27]. The mechanical alloying (MA) process is capable of producing nano‐sized structures, metallic alloys, composites, nano‐crystalline, and high‐temperature alloys [28, 29].…”