低氧分压系统及其在二元合金选择性氧化中的应用

A LOW OXYGEN PARTIAL PRESSURE APPARTUS AND ITS APPLICATION TO THE STUDY OF SELECTIVE OXIDATION OF BINARY ALLOYS

根据氧化锆陶瓷管材在高温（＞８７３Ｋ时，因管壁内外的氧分压不同形成氧浓差电池［Ｐｔ，Ｏ２（Ｐ）｜ＺｒＯ２｜空气（Ｐ），Ｐｔ］的原理，研制了可控氧分子（Ｏ２）发射量的低氧分压发生系统。用该系统对Ｎｉ２０Ｃｒ合金进行低氧分压顶氧化处理后，促进了Ｃｒ在１２７３Ｋ时的选择性氧化，提高了合金的抗氧化性能。在低氧分压下，Ｃｕ１．５Ａｌ合金发生了Ａｌ的选择性内氧化。

An apparatus which could provide a low oxygen pressure was developed. The unit worked on the basis of an oxygen concentration cell (-)Pt, O2(P)|ZrO2(s)|air(P ), Pt(+). The oxygen pressure at the outlet of the apparatus was dependent on temperature, discharge current of the Oxygen concentration cell (which, in turn, was determined by the external electrical resistance) and the flow volume of the carrier gas. Atmosphere thus produced was aPPlied to examine the selective okidation behavior of two binary alloys. Oxidation pretreatment of Ni20Cr under low oxygen pressure improved its oxidation resistance due to the selective oxidation of chromium. Internal oxidation of aluminium might take plaCe in Cu1.5Al under such a low Oxygen pressure.