IC-6高温合金的氧化性能与防护

OXIDATION AND PROTECTION OF SUPERALLOY IC-6

测定了IC - 6高温合金在 90 0℃～ 110 0℃的氧化动力学曲线 .结果表明 :90 0℃ ,IC - 6合金的氧化膜主要由α-Al2 O3 、NiAl2 O4 和NiO构成并含有少量的NiMoO4 和MoO2 .10 5 0℃和 110 0℃氧化时 ,IC - 6合金表面生成了挥发性很强的MoO3 ,发生了氧化失重 .IC - 6合金上沉积NiCoCrAlY涂层后 ,90 0℃时 ,涂层的氧化膜主要为α-Al2 O3 ;10 5 0℃时 ,氧化膜主要为α -Al2 O3 和Cr2 O3 ,大大改善了合金的抗氧化性 .110 0℃时 ,氧化膜主要由α-Al2 O3 、NiAl2 O4 和NiO构成 ,涂层虽然有一定的保护性 ,但效果不如 90 0℃和 10 5 0℃时显著 .形成以α -Al2 O3 和Cr2 O3 为主的氧化膜是使合金沉积NiCoCrAlY涂层后抗氧化能力大大提高的直接原因 .

NiCoCrAlY coating was deposited on a new Ni 3Al-base alloy IC-6 using arc ion plating.The oxidation kinetic curves of alloy IC-6,Ni-base alloy K17 and NiCoCrAlY coated alloy IC-6 at 900℃～1100℃ were obtained.The results indicate that exposed at 900℃,the oxide scales of alloy IC-6 consist of α-Al 2O 3?NiAl 2O 4 and NiO.A small amount of NiMoO 4 and MoO 2 were also detected.At 1050℃ and 1100℃,lose weight occurred due to the formation of volatile MoO 3.The oxidation weight gain rate of the NiCoCrAlY coating deposited on alloy IC-6 obeyed the parabolic rate law at different temperatures.The coating combined with alloy IC-6 closely and no spalling and void between the coating and the interface of the substrate were observed.The coating oxidation resistance remarkably improved with α-Al 2O 3 scales that formed and covered on the coating at 900℃ and both α-Al 2O 3 and Cr 2O 3 scales on the coating at 1050℃.The effectiveness of NiCoCrAlY coating was not distinctive at 1100℃ due to NiAl 2O 4 and NiO growing on the surface of coating.The formation of α-Al 2O 3 and Cr 2O 3 scale is the directly reason of remarkable improvement of oxidation resistance of superalloy IC-6 covered with NiCoCrAlY coating.