Study of the Structure of Oxide Interface in the Pt-Rh Alloy by AP-FIM

This paper reports the study of structure of oxide interface in Pt-Rh alloy by atom probe field ion micro-scope (AP-FIM) which is well suited for the study of atom distribution with atomic scale at the surface and in-terface of alloy. AP depth profiles show that oxide interface exist in the Pt-Rh alloy which consists of PtO,RhO, PrO_2 and RhO_2 . The mechanism of oxidation of the alloy is considered as that first oxygen moleculesadsorbed on-to the surface of alloy then dissociate into oxygen atoms (0_2→2O). Consequently oxygen atomsdiffuse into interior through grain boundary forming oxide (M+O→MO). When the concentration of oxygencontinuously increases the dioxide (MO+O→-MO_2) forms.     

AP-FIM STUDY ON THE MICROSTRUCTURES OF TiAl INTERMETALLIC COMPOUNDS FXBRICATED BY INGOT METALLURGY AND CENTRIFUGAL SPRAY DEPOSITION

1. IntroductionTitanium aluminide alloys based on the ac-TiAl phase are attractive materials for hightemperature structural application. The strength and ductility of two-phase TiAl alloys aremainly decided on microstructural size and morphologiesll32]. The mechanical propertiesof ac--TiAl alloys can be widely changed by microstructural control with millor alloyingand processing. It will be seen that an advanced processing, centrifugal spray deposition(CSD), can offer alloys with a refined…     

STUDY OF THE EFFECT OF BORON CONTENT ON THE ORDERED EXTENT OF THE Ni_3Al INTERMETALLICS COMPOUND BY AP-FIM

1. IntroductionPolycrystalline Ni3AI materials, an intermetallic compound with the L12 ordered structure, have been studied extensively in the past few years becallse of their potential application at high temperature structural applications. The brittle intergranular fractures andthe dramatic ductilizing effect of small amounts boron in polycrystalline Ni3AI led on tostudy the structure and chemistry of grain boundary[1--3]. The intergranular fragility ofNisAI alloys has been explained by…     

金属间化合和Ni3Al微结构的AP—FIM研究

用原子探针场离子显微镜（ＡＰ－ＦＩＭ）研究了添加Ｂ对Ｎｉ３Ａｌ有序度的影响以及不同Ｎｉ／Ａｌ比时Ｎｉ３Ａｌ场离子像衬度的变化。无Ｂ的Ｎｉ３Ａｌ样品中晶内出现富Ｎｉ区,且Ｎｉ富集程度的不同而影响场离子像的衬度。在Ｎｉ３Ａｌ样品中,Ｂ的添加会影响Ｎｉ３Ａｌ晶体的择优取向。随Ｂ含量的增加,Ｎｉ３Ａｌ中占据反位置的Ａｌ原子增多,有序度降低,Ｎｉ３Ａｌ样品有序度的降低是改善室温延展性的原因之一。     

金属间化合物Ni_3Al微结构的AP-FIM研究

用原子探针场离子显微镜（AP-FIM）研究了添加B对Ni3Al有序度的影响以及不同Ni／Al比时Ni3Al场离子像衬度的变化无B的Ni3Al样品中晶内出现富Ni区，且随着Ni富集程度的不同而影响场离子像的衬度在.Ni3Al样品中，B的添加会影响Ni3Al晶体的择优取向随B含量的增加，Ni3Al中占据反位置的Al原子增多，有序度降低Ni3Al样品有序度的降低是改善室温延展性的原因之一.     

THE EXPERIMENTAL STUDIES OF NiO CLUSTER FORMATION IN Ni_3Al ALLOYS BY AP-FIM

1. IntroductionFOr maily years, the room temperature brittleness of the polyer}l'stalline Ni3AI was recognized to be "intrinsically brittl.5,[1'2] due to brittle grain--boundary fracture. Recentlyit hajs been shown that environmental embrittlement is a major cause of the poor ductiLity of NiaAI in air[3--sl, and the embrittlement mechanism involves chemical .eactio.sfsl=M HzO-MO ZH or M HaO-MOH H. Where M is a reactive element in the intermetallic compound (Ni and Al) which reacts ch…