Nb. Morgan et Cm. Friend, Factorial design analysis of phase transformation stability in thermally cycled NiTi alloys, MAT SCI E A, 275, 1999, pp. 664-667
This paper considers the durability and stability of thermoelastic martensi
tic transformations in commercial NiTi alloys subjected to repeated heating
and cooling cycles. The experimental study was designed to mimic real actu
ator applications where the alloy is required to produce a work output. Thi
s was achieved by thermal cycling against constant loads and by studying th
e effect of repeated transformations on shape stability and strain output.
A factorial experimental method was employed which considered: thermal proc
essing, heating/cooling rates, applied loads and prior cold work. For the f
irst time, this paper attempts to analyse the main interactive effects and
individual significance of processing and operating factors on transformati
on stability and actuator output. The results presented can thus be used as
a guide to optimising the processing and operating conditions required for
long term actuator stability. (C) 1999 Elsevier Science S.A. All rights re
served.