Studies of the Effectiveness of Certain High Performance Coatings in Preventing Hot Corrosion Degradation of Ti-Aluminide Alloys

Dudziak Tomasz; Alasdair Wilson; Haifa G. Ahmad; Psantu K. Datta

doi:10.4028/www.scientific.net/DDF.289-292.437

Paper Titles

Diffusion of Oxygen in Thermally Grown Oxide Scales
p.405

Evaluation of Si Coating on Ferritic Steels by CVD-FBR Technology in Steam Oxidation
p.413

Graded Nitrogen Ingress in FCC Metallic Structures and the Related Microstructures and High Temperature Oxidation Behaviour
p.421

On the Mechanism of Cu₂O Oxidation at High Temperatures
p.429

Studies of the Effectiveness of Certain High Performance Coatings in Preventing Hot Corrosion Degradation of Ti-Aluminide Alloys
p.437

A Thermodynamic Approach of the Mechano-Chemical Coupling during the Oxidation of Uranium Dioxide
p.447

Oxidation Behaviour of Stainles Steel Matrix with TiC and TiC+TiB₂ SHS Powders in a Thermal Spray Process
p.455

Behaviour of Aluminide Diffusion Coatings on HCM12-A Steel by Al/Ce and Al/La CVD-FBR in Oxidation.
p.461

The Influence of CVD-FBR Coatings on HCM12 Corrosion Behaviour under Molten Salt Conditions
p.469

HomeDefect and Diffusion ForumDefect and Diffusion Forum Vols. 289-292Studies of the Effectiveness of Certain High...

Studies of the Effectiveness of Certain High Performance Coatings in Preventing Hot Corrosion Degradation of Ti-Aluminide Alloys

Abstract:

This paper originates from a large EU programme designed to produce high performance coatings with superior mechanical and corrosion resistance properties to enhance high temperature corrosion behaviour of TiAl based alloy (Ti45Al8Nb).The paper here is concerned with studies of the hot corrosion behaviour of Ti – Aluminide alloys (Ti45Al8Nb mainly -TiAl with small amount 2 (Ti3Al)) coated with three coatings: (1) TiAlYN/CrN coating, (2) CrAl with 2%YN addition [1,2] (3) TiAlN with Al2O3 overlayer. Hot corrosion was induced by spraying salts mixture of 80%Na2SO4/20%NaCl with melting point around 700oC [1] [2] on heated sample surfaces, and subsequently heating the sprayed samples in a furnace at 750oC for various times. The extent of degradation, assessed by weight changes and examination by OM (Optical Microscope), SEM (Scanning Electron Microscope), and EDX (Energy Dispersive X-Ray Analysis) indicated that all samples suffered hot corrosion attack to various degrees. TiAlN with Al2O3 overlayer had the best corrosion resistance.We shall discuss these results within a mechanistic framework of hot corrosion degradation and describe their implications.