EFFECT OF OXIDE GRAIN STRUCTURE ON HIGH-TEMPERATURE OXIDATION OF CR
EFFECT OF OXIDE GRAIN STRUCTURE ON HIGH-TEMPERATURE OXIDATION OF CR
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DOI：
10.1007/bf00611694
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发表时间：
1975-01-01
影响因子：
2.2
通讯作者：
SPROULE, GI
中科院分区：
文献类型：
--
作者：
CAPLAN, D;SPROULE, GI
在980、1090和1200°C下，Cr在1 aim O2中被氧化。电抛光的Cr和蚀刻的Cr的某些方向迅速氧化，并在生长的Cr2 O3中产生压应力;其他方向氧化缓慢，显然没有应力。断口的SEM观察表明，厚氧化物是多晶的，而蚀刻的Cr上的薄氧化物是单晶的。单晶氧化物是由阳离子向外晶格扩散生长的，多晶层是由阳离子向外扩散和阴离子向内扩散的双向输运沿着氧化物晶界生长的。随后在多晶层的主体内形成氧化物产生压应力并导致塑性变形引起的裂纹。通过阳离子晶格迁移的Cr的氧化的活化能为58千卡/摩尔。多晶Cr2 O3在Fe-26 Cr合金上形成，无论是电抛光还是蚀刻;氧化相应地迅速并伴随着压应力。
Cr was oxidized in 1 aim O2at 980, 1090, and 1200°C. ElectropolishedCrand some orientations of etched Cr oxidize rapidly and develop compressive stress in the growing Cr2O3; other orientations oxidize slowly, apparently free of stress. SEM examination of fracture sections shows that the thick oxide is polycrystalline whereas the thin oxide on etched Cr is monocrystalline. It is deduced that the monocrystalline oxide grows by lattice diffusion of cations outward, and the polycrystalline layer by the two-way transport of cation diffusion outward and anion diffusion inward along oxide grain boundaries. The consequent formation of oxide within the body of the polycrystalline layer generates compressive stress and leads to wrinkling by plastic deformation. The activation energy for oxidation of Cr by cation lattice transport is 58 kcal/mole. Polycrystalline Cr2O3forms on Fe-26Cr alloy, whether electropolished or etched; oxidation is accordingly rapid and accompanied by compressive stress.