Development of High-Temperature Corrosion and Creep Resistant Nb, Mo and Cr Based Compositions with Protective Self-Healing Coating of Fe-45%Cr-4%Al-1%Ni-0.3%La Alloy

In this work the results of the experimental studies of new composite materials based on refractory metals with protective coatings of alumina forming Fe-45%Cr-4%Al-1%Ni-0.3%La alloy are given. The compositions with optimal correlation of heat resistance and heat proofness were obtained on the Nb and Mo monocrystals and polycrystalline low alloyed Cr bulk samples coated with Fe-45%Cr-4%Al-1%Ni-0.3%La alloy using the electron-beam vacuum evaporation technique. Obtained compositions were investigated using the SEM, WDS, AES, XRD and LM. The results of the tests demonstrated that the metallic-oxide hybrid coating layer formed on the surfaces of synthesized composition materials, at high working temperatures have an ability to heal the cracks developed as a result of mechanical and thermal damages. Moreover, the developed coating material is characterized by high adhesion with the metallic substrates, and therefore it has protective features against high temperatures, corrosion and a wear. The obtained compositions can be considered as an effective engineering material for specific applications where the parts and devices manufactured from this material will have thermal activated self-healing surface and will be able to work for a long time in ordinary and other aggressive ambient with variable thermal and mechanical loading conditions at temperatures as high as 1,000-1,200^OC.