F.GESMUNDOS.WANGY.NIU
中国腐蚀与防护学报
This paper presents an analysis of the conditions of stability of the different forms of internal oxidation of ideal ternary A-B-C alloys, where A is the most noble and C the most reactive component, forming insoluble oxide and exposed to high pressures of a single oxidant. The treatment, based on an extension to ternary alloys of Wagner’s criterion for the transition from internal to external oxidation in binary alloys, allows to predict the existence of three different forms of internal oxidation. In fact, in addition to the most common kinds of internal attack, involving the coupled internal oxidation of B+C beneath external AO scales and the internal oxidation of C beneath external BO scales, a third mode, involving the internal oxidation of C beneath external scales composed of mixtures of AO+BO, becomes also possible under special conditions. A combination of the boundary conditions for the existence of these different types of internal oxidation allows to predict three different kinds of complete maps for the internal oxidation in these systems, one of which involves only two modes, while the other two involve all the three possible modes of internal oxidation.
关键词:
ternary alloy
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null
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null
薛云龙
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李双明
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李克伟
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张婷
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傅恒志
稀有金属
考察了Cr2Nb-20Ti(原子分数,下同)合金在5,10,20,100 μm/s 4种定向凝固速率下的组织演变,研究结果表明:各凝固速率下合金的组织均由C 15-Cr2Nb枝晶和枝晶间β-Ti构成,高温相β-Ti的形成是由Cr起到稳定化作用所致.随着凝固速率的增加,C 15-Cr2Nb板条枝晶逐渐分裂,形貌由粗大板条转变为不规则多边形,同时凝固速率越大,扰动波长越小,枝晶组织越细,枝晶生长方向越偏向择优取向.实验中C 15-Cr2Nb的择优生长晶面为(220),因该晶面有较大的裸露键能,生长时处于优势而淘汰其它生长晶面.
关键词:
三元合金
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定向凝固
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组织演变
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Cr2Nb枝晶
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择优取向
赵泽良
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牛焱
腐蚀学报（英文）
研究了Cu-15Ni-15Ag合金在600～700℃空气中的氧化 .合金由富Ag的α相与Cu-Ni固溶体β相组成；氧化速率基本服从抛物线规律，合金的成膜速 率与纯Cu氧化近似.不同温度下合金均形成了最外层为CuO，内层为Cu2O，NiO以及Ag颗粒 组成的复杂氧化膜.在700℃氧化时观察到典型的Ni的内氧化，同时，由于Ni优先溶解于CuO 中影响了CuO-Cu2O氧压平衡，导致形成了CuO位于Cu2O下的特殊氧化膜结构.
关键词:
三元合金
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Cu-Ni-Ag
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two-phase
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oxidation
