Microstructural evolution of mechanically alloyed Ni-based alloys under high temperature oxidation

摘要: Abstract To further improve the cost-benefit of MCrAlX (X is a reactive element like Y, Hf, Ta, etc.) alloys, microhardness, microstructure and oxidation behavior two Ni-based Ni60Co30Al10 Ni60Co10Cr20Al10 without elements were studied by scanning electron microscopy, X-ray diffraction microhardness Vickers. These alloys synthesized mechanical alloying in high energy ball mill conventional sintering at 1100 °C under inert atmosphere. Milling time Cr additions have significant effect on as-milled sintered samples. Bulk samples oxidized 1000 °C for different times to analyze possible growth protective oxide scale, as well addition chemical composition scale. After 3 h formation Al2O3 scale alloy evident. By reducing Co content incorporating 20 wt.% Cr, an with presence Cr2O3 was observed. Even homogeneous, continuous products surface evident, microstructural changes after treatments decrease both alloys.