Isothermal Oxidation Behavior of Zr-Y Coating on γ-TiAl by Double Glow Plasma Surface Metal Alloying Technique

Abstract

Oxidation resistance of Zr-Y coating on γ-TiAl alloy prepared by a double-glow plasma surface alloying technique was investigated in static air at 750 °C, 800 °C and 850 °C for 100 h. A pure Zr coating was also prepared for comparison. Addition of Y improved high-temperature oxidation resistance of the alloying coating because of its refining effect and inhibition of cationic diffusion. Oxidation kinetic curves indicated that the high-temperature oxidation resistance of the Zr-Y coating was about eight times higher than that of the bare substrate and about 3 times higher than that of pure Zr coating.

Effect of Heating Treatment on the Microstructure and Properties of Cr–Mo Duplex-Alloyed Coating Prepared by Double Glow Plasma Surface Alloying

“…Double glow plasma surface alloying (DGPSA) is a relatively new surface strengthening technology used mainly to prepare various metal alloying layers [10][11][12]. The ions operating under abnormal glow discharge conditions are accelerated by an electric field, producing a strong bombardment effect on the cathode and target.…”

“…This ion bombardment causes sputtering of the target, and the sputtered alloy atoms move toward the surface of the workpiece under the action of the electric field, magnetic field, and gravity, resulting in the formation of coatings. Moreover, DGPSA is carried out at high temperatures, and the atoms between the coating and matrix diffuse mutually, resulting in metallurgical bonding between the coating and the substrate and thereby improving the adhesion of the coating [10]. Compared with thermal spraying, magnetron sputtering, chemical vapor deposition (CVD), and physical vapor deposition (PVD), DGPSA has the advantages of controllable thickness, strong bonding force, and few defects such as voids and cracks [12][13][14].…”