Study of the martensitic transformation in the Hafnium-Palladium system

Abstract

Abstract. High temperature shape memory alloys have received a large interest for many years but none of the systems studied so far has led to industrial applications. Those alloys are expected to develop an actuating role in high temperature environment as for example aircraft turbines. Lots of criteria are required in order to substitute or optimize heavy existing actuators. Here are presented a few results obtained with the system hafnium-palladium, not so documented for the moment, that develops a martensitic transformation at around 773 K. According to the characteristics of very well-known alloys such as NiTi, some compositions around the equiatomic are explored. The main objective of our work is to know the influence of a stoechiometry gap on the microstructure of the alloys and the martensitic transformation.

On the potential of Ti50Au50 compound as a high temperature shape memory alloy

“…In this later, a better control of the air flows in jet engines by SMA actuators according to the portion of the flight envelope could enhance the output in order to reduce the oil consumption or decrease the noise pollution [2,3]. Many metallic systems like CuAlNi, NiAl, and more recently Ru-based alloys [4,5], and HfPd system [6] presenting a martensitic transformation at high temperature have been studied as potential shape memory alloys. Also, a partial or total substitution of nickel or titanium in NiTi by a heavier element increases the transformation temperatures.…”