Abstract
The addition of boron to Ni/sub 3/Al has produced a fabricable material with good high temperature properties. Some substitutional elements have also been added to the base material to further refine its properties for particular applications. One aspect in understanding the influence of these additions is to determine the distribution of the substitutional elements between the nickel and aluminum sites of the ordered Ll/sub 2/ lattice. The atomic spatial resolution of the atom probe field-ion microscope (APFIM) permits the site occupation probability of substitutional elements and the local degree of order to be measured directly. These parameters are determined by measuring the composition of successive planes in the ordered lattice. The site occupation probability is calculated from the preference of the substitutional elements between the different atomic layers in the ordered structure. One advantage of this technique is that it can be applied to normal polycrystalline materials and does not require the specimen to be a single crystal. This technique can only be used to determine the site occupation probability for elements that substitute in the ordered lattice. Three substitutional elements, hafnium, iron, and cobalt, were selected for this study because of their anticipated different site preference.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
