摘要
研究了铸态 Ni_3Al 合金及其微晶溅射涂层在1000—1100℃下等温氧化性能及1000℃下的循环氧化性能。结果表明:铸态 Ni_3Al 合金在氧化过程中形成 Al_2O_3,NiO 和 NiAl_2O_4 的复杂氧化膜;微晶 Ni_3Al涂层在氧化过程中形成α—Al_2O_3和 NiAl_2O_4尖晶石,不含 NiO,这种氧化膜的保护作用比含 NiO 的氧化膜的保护作用好,使得其氧化增重比铸态合金小约1半。此外铸态 Ni_3Al 合金在氧化过程中沿粗大晶界发生严重的内氧化,且表面氧化膜较脆易发生剥落;微晶 Ni_3Al 涂层可以消除沿晶界的内氧化,氧化膜与基体粘附良好,未发现剥落现象。微晶化大大提高了 Ni_3Al 合金的抗氧化性能。
In this paper,isothermal oxidation at 1000—1100℃ and cyclic oxidation at1000℃ were investigated in air.The results indicate that the cast Ni_3Al alloy formed Al_2O_3,NiO and NiAl_2O_4 complex oxide scales during oxidation,while sputtered Ni_3Almicrocrystalline coating formed Al_2O_3 and NiAl_2O_4 oxide scales without NiO,which weremore protective than those formed on the cast alloy with NiO.As a result of this,the massgain of the latter was much less than that of the former.Moreover,severe internal oxidationtook place in the cast Ni_3Al alloy along the coarse grain boundaries and scale spallation wasfound,while for its microcystal,neither internal oxidation nor scale spallation was observed.The oxidation resistance of Ni_3Al alloy is markedly improved by microcrystallization.
基金
国家自然科学基金 59071025
国家科委863资助项目
