摘要
A Co32Ni21Cr8Al0.5Y alloy(by mass percentage)has been additively manufactured by selective laser melting(SLM).The as-deposited alloy has aγmatrix dispersing Al-rich β phase which is coarsened with time at high temperatures.The alloy grows a double-layered oxide scale consisting of outer(Co,Ni)(Cr,Al)_(2)O_(4) and inner Al_(2)O_(3) during 1000 h isothermal oxidation in air at 900 and 1000℃.The Al_(2)O_(3) growth is dominated after a short term,particularly at the higher temperature.The growth rate of inner Al_(2)O_(3) layer during cyclic oxidation with respect to isothermal oxidation at 1000℃appears to be promoted,leading to extensive incorporation of Y-rich particles into the alumina-dominated scale.The CoNiCrAlY alloy mainly forms a major Al_(2)O_(3) scale after 40 h during hot corrosion at 800 and 900℃under Na_(2)SO_(4)+NaCl mixture.The dependence of the microstructure of the oxide scales formed on the different corrosion conditions is fully discussed.
基金
financially supported by the Jiangxi Provincial Key Research and Development Program of China(No.20192ACB80001)
