High‐temperature corrosion of mechanically alloyed Cr–AlSi12 composite coatings on Ti–6Al–4V alloy substrate

Abstract

In the present work, the Cr-AlSi12 composite coatings were successfully synthesized on the Ti-6Al-4V alloy substrate by using the mechanical alloying method. The effects of raw Cr particle size, milling duration, and annealing treatment on the preparation of the coatings were investigated. The asprepared coatings consisted of the inner coating layer with coarse Cr particles and the outer coating layer with refined and highly homogenized structure. The annealing treatment could promote element diffusion and alloying; it was favorable to the densification and oxidation resistance of the coatings. There is a highly densified alloyed layer in the outer coating. The annealed coating showed excellent friction and wear resistance. After the oxidation process, the annealed coating showed the best high-temperature oxidation resistance. The oxidized annealed coating exhibited four layers, which included the thin Al 2 O 3 oxide film, the homogenized alloyed layer, the composite layer consisted of Al 2 O 3 and coarse Cr particles surrounded by alloyed layer, and the Al 3 Ti diffusion layer. This was favorable to the improvement of high-temperature oxidation resistance. The oxidation process of the annealed coating was elaborated.

Investigation of Cu-diamond/Cu-diamond-high-entropy alloys bi-layer coating via mechanical alloying

“…10 Compared to other coating deposition techniques, MA can avoid defects caused by metallurgical reactions. 20 At the same time, metal matrix composite (MMC) coatings have received much attention as a ductile-brittle system, in which some ductile materials (such as Fe, 21 Cu, 22 et al) are used as binders and various reinforcement phases such as HEAs, 23 TiC, 24 WC 25 and TiO 2 2 are added to obtain excellent mechanical or thermal properties. Therefore, the MA method is attractive for the preparation of bilayer coatings.…”

Effects of carbon addition on Ti–Al–Si coatings synthesized by self‐generated gradient hot‐dipping infiltration method

“…The advantages of low density, high specific strength, and stable medium temperature performance make it more preferred in aerospace, automotive, chemical processing fields, and other applications. [1][2][3] Due to the dense TiO 2 oxidized layer on the surface, the Ti-6Al-4V alloy exhibits excellent oxidation resistance below 420°C. [4] However, as the temperature increases, the TiO 2 oxidized layer gradually transforms into a nonprotective state, [5] which directly affects the application of Ti-6Al-4V alloy in high-temperature devices such as aero-engine components and high-temperature chemical sensors.…”