O'Donoghue, L; Gandhi, AA; Butler, J; Redington, W; Tiernan, P; McGloughlin, T; Carlson, JC; Lavelle, S; Tofail, SAM

2010

February

Nuclear Instruments & Methods In Physics Research Section B-Beam Interactions With Materials And Atoms

X-ray and microstructural investigation of NiTiPt alloys homogenised at intermediate to high temperatures

Published

()

NiTiPt XRD Microstructure Nitinol DTA Hardness

268

3-4

287

290

The structural evolution of a Ni-rich NiTiPt alloy (Ni(50)Ti(42.5)Pt(7.5)) is studied here as a function of homogenisation temperature. The biphasic microstructure of the as-cast Ni(50)Ti(42.5)Pt(7.5) alloy consisted of a high-Pt lath type structure that was dispersed in a martensitic NiTiPt matrix. Homogenisation of the as-cast structure at intermediate temperatures (825-925 degrees C) resulted in the redistribution of the dendritic second phase into a faceted structure. The hardness of the alloy decreased with increasing temperatures within this intermediate homogenisation temperature range due to breaking of the as-cast structure. Homogenisation of the alloys at higher temperatures e.g. 1100 and 1200 degrees C, resulted in the reformation of a lathed structure with an associated precipitation hardening due to the due to the formation of fine Ni-rich precipitates. (C) 2009 Elsevier B.V. All rights reserved.

0168-583X

10.1016/j.nimb.2009.07.015