Preparation of Ti-Al-Si Gradient Coating Based on Silicon Concentration Gradient and Added-Ce

Abstract

Titanium and titanium alloys have excellent physical properties and process properties and are widely used in the aviation industry, but their high-temperature oxidation resistance is poor, and there is a thermal barrier temperature of 600 °C, which limits their application as high-temperature components. The Self-generated Gradient Hot-dipping Infiltration (SGHDI) method is used to prepare the Ti-Al-Si gradient coating based on the silicon concentration with a compact Ti(Al,Si)3 phase layer, which can effectively improve the high-temperature oxidation resistance of the titanium alloy. Adding cerium can effectively inhibit the generation of the τ2: Ti(AlxSi1−x)2 phase within a certain hot infiltration time so as to form a continuous dense Al2O3 layer to further improve the oxidation resistance of the coating. Studies have found that multiple Ti-Al binary alloy phase layers are formed during the high-temperature oxidation process, which has the effect of isolating oxygen and crack growth, and effectively improving the high-temperature resistance of the coating oxidation performance.

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

“…In a similar research, Wang et al [ 33 ] investigated the effects of cerium addition on the self‐generated Ti–Al–Si coating. He showed that for a certain period, only a Ti(Al,Si) 3 phase layer was formed on the surface of the Ti–6Al–4V alloy.…”

“…Moreover, the Ti 5 Si 3 phase not only has good stability but also has a pinning effect, which can improve the adhesion of the oxidized coating. [32] In a similar research, Wang et al [33] investigated the effects of cerium addition on the self-generated Ti-Al-Si coating. He showed that for a certain period, only a Ti (Al,Si) 3 phase layer was formed on the surface of the Ti-6Al-4V alloy.…”

A Study on the High-Temperature Molten Salt Corrosion Resistance of Hot-Dip Aluminum/Carburizing Composite Coating on Ti65 Titanium Alloy

“…The reason for the appearance of these three hot-dip aluminum phases is the interdiffusion of the Al and Ti atoms between the composite substrate and TiAl3 coating with the extent of corrosion time. The formation of the transition diffusion layer of TiAl2, TiAl, and Ti3Al can reasonably reduce crack propagation or development, so the crack does not extend to the substrate [51]. 3 are the atomic content ratios corresponding to those indicated in Figure 7b.…”

Study on the Effect of Carburizing on the Microstructure and High-Temperature Oxidation Properties of Hot-Dip Aluminum Coating on Titanium Alloy

“…By adjusting the process parameters, different combinations of ductile TiNi and hard Ti 2 Ni intermetallic phases can be synthesized on the Ti-6Al-4V surface to obtain adjustable surface properties. Hot-dip aluminizing is a mature and extensible process [13,14]. Wang, Z. et al [14] prepared a Ti-Al-Si gradient coating based on silicon concentration gradients and added Ce to modify the coating.…”

“…Hot-dip aluminizing is a mature and extensible process [13,14]. Wang, Z. et al [14] prepared a Ti-Al-Si gradient coating based on silicon concentration gradients and added Ce to modify the coating. The coating has a dense Ti(Al,Si) 3 phase layer, which can effectively improve the high-temperature oxidation resistance of titanium alloys.…”