Published online by Cambridge University Press: 31 January 2011
Implantation of Ta into single crystal Ni3Al was conducted to determine the degree of surface hardening in monolithic alloys in relation to its lattice location. Ta was implanted at 400 keV to doses of 0.07, 0.36, and 2.52 × 1016 cm−2 along the [100] axis of a [100] crystal of Ni3Al at room temperature. Composition versus depth profiles were determined by RBS, and lattice location of Ta was determined by channeling angular yield scans about the [100] axis. The hardness of the surface was measured by ultra-low load indentation. Results show that implantation softens the surface and that the Ta is randomly distributed between Ni and Al sites. Annealing at 1000 °C/1 h significantly reduces the damage and causes preferential occupation of Al sites by Ta, resulting in a slight increase in surface hardness. Further annealing at 1200 °C/0.25 h increases the surface hardness substantially and increases occupation of Al lattice sites to roughly 84%. Results are consistent with a model in which the as-implanted surface is softened by disordering, and subsequent diffusion of Ta to Al sites during thermal treatment causes hardening of the surface.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.