Martensitic transformations and the shape memory effect in Ti50Ni10Au40 and Ti50Au50 alloys
Journal
Metallography
Journal Volume
20
Journal Issue
3
Pages
359-376
Date Issued
1987
Author(s)
Abstract
Martensitic transformations in Ti50Ni10Au40 and Ti50Au50 alloys are of the type B2 a3 B19(2H) as found in a Au-47.5%Cd alloy. The Ms temperatures of the Ti50Ni10Au40 and Ti50Au50 alloys are 440°C and 610°C, respectively. The martensite in both alloys is orthorhombic (2H) and identified as a modified B19 structure with secondary layer stacking at ( a 2.60, 0, c 2). The morphology of the martensite is spearlike with (111)M internal twins. In the Ti50Au50 martensite, (100)M stacking faults and type II twins are also found. Both Ti50Ni10Au40 and Ti50Au50 alloys exhibit a one-way shape memory effect, but not a two-way memory. This may result from the fact that the accumulated "bias" stresses are released when the temperature is raised to above As during the "training" process. © 1987.
Type
journal article