Effect of Pore Size on the High-temperature Oxidation Property of Ni-Cr-Al Based Powder Porous Metal

Abstract

The present study examined the effect of pore size on the high-temperature oxidation properties of Ni-Cr-Al based powder porous metals (pore sizes: 480 um and 1200 um). The porous metals consisted f y-Ni, y-Ni3Al, and B-NiAl phases. TGA experiments were conducted for 24 hours under twemperature conditions of 900, 1000 and 1100C in a 79% N2, + 21% )2 gas atmosphere. Oxide weight gain increased as temperatures increased. As pore sizes increased, more-excellent oxidation resistance was confirmed. After the high-temperature oxidation experiments, microstructures analysis showed that a-Al2O3 was a primary oxide and that Cr2O3 and NiCr2O4 were also formed.