(γ'+β)two-phase Ni-Al is a promising high-temperature protective coating material used on Ni-base su-peralloys since it has good interfacial compatibility with superalloys due to the low Al content compared to single-phaseβ-NiAl.In this paper,we aim to improve the oxidation resistance,whereby Ni-34Al-0.1Dy,a(γ'+β)two-phase Ni-Al alloy,was treated by laser shock processing(LSP)and the oxidation behavior at 1150℃was investigated.The results showed that after oxidation,Al2O3 scale formed on the original β phase of the untreated alloy with a small grain size(200-800 nm),while for the LSP-treated sam-ples,the scale grown on the original β phase was dominantly composed of larger Al2O3 grains with a size of 2-3 μm.The distinction was attributed to the promotion of θ-Al2O3 to α-Al2O3 transformation induced by the LSP,because the dislocation density,as well as surface roughness,were increased during LSP treatment which can provide heterogeneous nucleation sites for α-Al2O3.In addition,the larger-size Al2O3 particles,derived from the direct conversion of needle-like θ-Al2O3 in the initial oxidation stage,could rapidly overspread the whole β phase surface thus reducing the scale growth rate.

Bangyang Zhou;Jian He;Qijjie Zhou;Hongbo Guo

School of Materials Science and Engineering,Beihang University(BUAA),Beijing 100191,China;Research Institute for Frontier Science,Beihang University(BUAA),Beijing 100191,China;Key Laboratory of High-Temperature Structural Materials & Coatings Technology(Ministry of Industry and Information Technology),Beihang University(BUAA),Beijing 100191,China

材料科学技术（英文版）

[1]Bangyang Zhou;Jian He;Qijjie Zhou;Hongbo Guo-.Effects of laser shock processing on θ-Al2O3 to α-Al2O3 transformation and oxide scale morphology evolution in(γ'+β)two-phase Ni-34Al-0.1Dy alloys)[J].材料科学技术（英文版）,2022(14):157-166

34Al,1Dy,peralloys,overspread

Effects,laser,shock,processing,Al2O3,transformation,oxide,scale,morphology,evolution,two,phase,promising,high,temperature,protective,coating,material,used,base,since,good,interfacial,compatibility,superalloys,due,low,content,compared,single,NiAl,In,this,paper,aim,improve,oxidation,resistance,whereby,was,LSP,behavior,investigated,results,showed,that,after,formed,original,untreated,small,size,while,sam,ples,grown,dominantly,composed,larger,grains,distinction,attributed,promotion,induced,because,dislocation,density,well,surface,roughness,were,increased,during,treatment,which,can,provide,heterogeneous,nucleation,sites,addition,particles,derived,from,direct,conversion,needle,like,initial,stage,could,rapidly,whole,thus,reducing,growth,rate

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