Phase transformation control of powder metallurgy super-elastic TiNi alloy by adding CO element+1
Journal article
Authors/Editors
Strategic Research Themes
No matching items found.
Publication Details
Author list: Eda T., Khantachawana A., Umeda J., Kondoh K.
Publisher: Nihon Kinzoku Gakkai (日本金属学会)
Publication year: 2019
Journal: Materials Transactions (1345-9678)
Volume number: 60
Issue number: 8
Start page: 1583
End page: 1590
Number of pages: 8
ISSN: 1345-9678
Languages: English-Great Britain (EN-GB)
View in Web of Science | View on publisher site | View citing articles in Web of Science
Abstract
In order to improve the controllability of the mechanical properties of powder metallurgy (PM) titanium (Ti)-nickel (Ni) super-elastic alloys, cobalt (Co) powder was added to the alloys up to 2.0 at%. In particular, the dependence of plateau stress and recovery rate in tensile hysteresis test on cobalt content was investigated by considering microstructures analysis results. XRD and TEM-EDS analysis clarified cobalt elements existed as substitutional solution atoms in Ni atom sites of TiNi alloys. It was confirmed that PM TiNiCo alloys with the cobalt content of 1.0 at% Co or less showed a high shape recovery rate of around 90% or more. In addition, the increment of the plateau stress of TiNiCo alloys was almost constant regardless of the holding time in heat treatment. That is, the cobalt solution content had no effect on the amount and size of Ti3Ni4 precipitates. Therefore, it was possible to independently control the plateau stress without affecting the critical slip strain by adding cobalt element to TiNi alloys. ฉ 2019 Japan Society of Powder and Powder Metallurgy
Keywords
Shape memory property, Super-elastic, Titanium-nickel-cobalt alloy
Contact Information