Microstructure and Thermoelastic Martensitic Transformation in Ni-Low and -Rich Ni–Ti–Hf–Nb Hightemperature Shape Memory Alloys
摘要
The paper studies the alloying effect of the quenched Ni-low (Ni49.5Ti35.5Hf15)100–XNbX and Ni-rich (Ni50.3Ti34.7Hf15)100–XNbX alloys (X = 0, 15 at.% Nb) on the B2-B19' martensitic transformation, viscoelastic properties and microstructure. Alloying of Ni-low and -rich alloys with Nb, provides the β-Nb phase precipitation within the (Ti, Hf)2Ni phase. After alloying, the transformation temperature and austenite elastic modulus decrease in Ni-low alloys and increase in Ni-rich alloys, thus making them similar.