Modification Of NiCoCrAlY Coating And Alloying Of Al Film With High Current Pulsed Electron Beam

In the last few decades,high current pulsed electron beam(HCPEB) has been developed intensively as a new high-power energetic beam used for surface modification of materials. The article is divided into two parts,one is that DZ4 and GH33 substrates were coated with NiCoCrA1Y by plasma spray,the other one is to use the multi-arc ion to plate the method to deposit A1 film with 3μm on the DZ4 alloy.Subsequently treated by high current pulsed electron beams(HCPEB) of different parameters.The surface microstructure,phase structure,high temperature oxidation resistance and corrosion were studied.Analyze the performance and the structure of the NiCoCrA1Y coating before and after HCPEB irradiation.The surface of NiCoCrAlY coating prepared by plasma spray is loosen with many holes and inanitions.The SEM results showed that as a result of the HCPEB treatment the loose and rough structure remelted and the surface became smooth Micro-smooth,craters and cracks appeared on the surface.With the increasing of the accelerating voltage and the pulses,the surface of the NiCoCrAlY coating remelted more adequately.The XRD results showed that the NiCoCrAlY coatings by plasma spray are the hexagonal system Ni_3.55Co_0.5Cr_0.2Al_0.75Y,theγphase andγ' phase manifolded and there was no visible thermal stress.The oxidation test at 900℃for 100h showed that a more compact and successiveα-Al₂O₃ scale was formed on the surface of the samples after HCPEB irradiation,which made the oxidation resistance of the NiCoCrAlY coatings improve obviously.Uses the multi-arc ion to plate the method to deposit Al film on the DZ4 alloy.The SEM results of the sample before and after the HCPEB treatment,Al film of the origin sample was loose,became has leveled after 1 pulse treatment,along with the pulse frequency increase,the superficial was more and more smooth after 10 pulse treatment had the obvious micro crack appearance.After the electron beam radiation treatment the melt pit and the eruption phenomenon appear,the phenomenon after 5 pulse was most obvious.The glancing incidence XRD analysis indicated that,as a result of the thin film and the substrate mix,as the pulse frequency increases,the content of Al reduces,the content of substrate Ni increases,the crystalless ingredient appears when pulse processing once,and after pulse processing many times the NiAl new phase appears,which is advantageous in the thin film anti-corrosive performance enhancement.After the electron beam exposure,the anti-corrosive performance of the Al membrane enhances obviously,which enhances approximately 70%from the corrosion electric potential.The research work shows that HCPEB used for surface modification of materials has great application prospects in thick film and alloying of thin film.