Deformation measurement and simulation of Ti–6Al–4V blades induced by shot peening process

Abstract

The shape and deformation of the blades play important roles in the aerodynamic performance of aeroengines, which results from the plastic deformation and the residual stresses after complex manufacturing processes, especially the shot peening. However, few studies were focused on the detailed strategies of the shot peening on the complex pro le and the superposition effects of residual stresses during the entire manufacturing processes. In this paper, based on the concept of eigenstrains, we investigated the effect of shot peening on the residual stress and deformation of the blade by combining the experimental measurement and the local-global simulation. The results show that the initial residual stresses induced by the previous milling process could be neglected. After the shot peening, the blade has the largest deformation amount if considering the initial residual stresses during milling with large scale material removal, when compared with no initial residual stresses and initial residual stresses after dynamic milling of blades. Furthermore, the In-out sequence of shot peening results in the smallest deformation, and the pre-deformation of the blade can effectively offset this deformation. Finally, the shot peening strength should not be too high in practical blade manufacturing when the thickness is too thin, which may be a great threat to the reliability and safety of blades.

Influence of Silicon and Chromium on the Na2SO4-Induced Hot Corrosion Behavior of Titanium Alloys

“…According to thermodynamic calculations [48], SiF 4 has the highest partial pressure in a pack activated by fluorides, but it could not react according to Reaction (5), because it was a silicon fluoride in its highest oxidation state and, therefore, could only participate in the transport of fluorine back to the powder pack. To check the most probable reactions, selected standard Gibbs free energies at 850 • C were calculated based on the available thermodynamic data [49]:…”

“…Ti-6Al-4V [wt%], representing this group of alloys, is the most popular titanium alloy due to its unique balance of mechanical and corrosion properties, which can also be optimized using heat treatments. In the aerospace industry, Ti-6Al-4V is a constructional material; for example, it is used for airframes, and it is used as a component of engines, e.g., compressor blades [4][5][6]. Its biocompatibility makes this alloy also useful for biomedical applications [7,8], such as knee and hip joints [9,10] and dental implants [11].…”