Long-term oxidation behavior and mechanism of DD6 Ni-based single crystal superalloy at 1050 °C and 1100 °C in air

Oxidation Behavior of the Nickel-Based Superalloy DZ125 at 980 °C

“…EDS analysis showed that oxides formed on the surface can be roughly classified into two types as marked by 1, 2 and 3. The black region (point 3) was mainly consisted of Al and O element, which is in accordance with the references: in superalloy with high contents of Cr, the continuous alumina film would form on the alloy surface when the content of Al is higher than 5% [17][18][19]. Whereas the Ni was rich in plate-like oxides which were randomly distributed on the surface (point 1), Ta and Hf were the major metallic constituents of the white isolated island particles (point 2).…”

“…6. After oxidation for 0.5 h, a thickness of 1.2 lm c 0 -free zone accompanied by alumina layer was observed in the specimens; it was generally considered that the diffusion of Al by its own concentration gradients induced the oxidation reaction resulted in the formation of c 0 -free zone on the beneath of oxide film [12,17,18,20]. As the oxidation time increased, the total oxide layer showed faster growth rate than that of c 0 -free zone.…”

“…It was apparent that the oxidefilm growth on the specimens proceeds by a rapidly increased at initial stage followed a gradually reduction stage of the oxide-film growth rate, especially after oxidation for 55 h, the oxide growth rate drastically decreased. The relationship between mass change and exposure time during oxidation usually follows an approximate power law [12,14,17], which can be described as…”

“…Pfennig and Fedelich [14] found that two distinguished oxidation stages are observed when they studied the oxidation behavior of single crystal PWA1483. Pei et al [17] reported that the oxidation behavior of DD6 can be roughly divided into three stages resulting from the spalling of the oxide film as the exposure time increased. Although the oxidation kinetics of the superalloy has been widely studied, only few studies on the mechanism of kinetics and no pay attention to the relationship between the oxide growth and the oxidation kinetics at the different exposure time.…”

Numerical Simulation on Pulsed Laser Ablation of the Single-Crystal Superalloy Considering Material Moving Front and Effect of Comprehensive Heat Dissipation

“…The DD6 single-crystal superalloy is the second generation of nickel-based single-crystal superalloy in China and possesses the advantages of good high-temperature mechanical properties, good long-term microstructure stability and good casting properties [ 22 , 23 , 24 ]. The DD6 single-crystal superalloy could be applied to fabricate high-temperature components such as working blades of gas turbines with complex internal cavities.…”