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球磨 8 0～ 2 0 0h的Ni-Ag合金粉末经热压烧结后获得了晶粒尺寸小于 5 0nm的Ni- 5 0Ag纳米晶块体材料 ,经热处理后其晶粒长大约至 10 0nm .在 6 0 0℃的高温氧化时 ,合金呈现出不同的氧化膜结构及氧化增重速率 .MA 80hNi- 5 0Ag和MA 2 0 0hNi- 5 0Ag合金在 6 0 0℃空气氧化时均未形成选择性的外氧化膜 ,而形成了非平衡态复杂内氧化结构 .热处理前 ,合金的氧化行为受晶粒尺寸以及合金内部缺陷 ,内应力等诸多因素的影响 ,导致MA80h和 2 0 0h合金不同时间合金氧化速率常数相差较大 .而经热处理后 ,主要是晶粒尺寸影响合金的氧化行为
After Ni-Ag alloy powder with 80 ~ 200h of ball milling was sintered by hot-pressing, Ni-50Ag nanocrystalline bulk material with grain size less than 500nm was obtained. After heat treatment, the grain size increased to about 100nm. When the alloy is oxidized at 600 ℃, the alloy exhibits different oxide film structure and oxidation rate. The selectivity of MA 80hNi-50Ag and MA 2o 0hNi- Of the outer oxide film, and the formation of a non-equilibrium complex internal oxidation structure before heat treatment, the oxidation behavior of the alloy by the grain size and internal defects of the alloy, internal stress and many other factors, resulting in MA80h and 200h alloy alloy at different times The oxidation rate constant is quite different, but after heat treatment, the grain size mainly affects the oxidation behavior of the alloy