Nanoindentation studies on precipitation hardening of Ti-rich Ti 50.4Ni49.5Si0.1 shape memory ribbons
Journal
Intermetallics
Journal Volume
36
Pages
109-117
Date Issued
2013
Author(s)
Abstract
Precipitation hardening effect in Ti-rich Ti50.4Ni 49.5Si0.1 shape memory ribbons is investigated. The hardness of the ribbon aged at 773 K for 1 h reaches a maximum. TEM observations show the as-spun ribbon is strengthened by nanoscale Ti2Ni precipitates and the ribbon aged at 773 K for 1 h is hardened by the coexistence of dense nanoscale Ti2Ni and Ti3Ni4 precipitates. The Ti3Ni4 formation is closely related to the Si content in the ribbons, which enhances the Ti2Ni formation and thus makes the matrix Ni-rich. The ribbon aged for 1 h exhibits excellent reversible strain of shape memory effect and remnant depth ratio of pseudoelasticity. The nanoscale Ti2Ni and Ti3Ni 4 precipitates in aged Ti50.4Ni49.5Si 0.1 ribbons show not only significant precipitation hardening but also a substantial improvement in the functionality of the TiNi ribbons. © 2013 Elsevier Ltd. All rights reserved.
Type
journal article