ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
A series of multielementary AB-type shape memory alloys, quaternary (Ti,Hf)50(Ni,Cu)50and quinary (Ti,Zr,Hf)50(Ni,Cu)50, have been produced by means of the melt-spinning (ribbons),twin-roll casting (strips) and injection casting (bars) techniques. The glass forming ability (GFA)has been investigated by means of calorimetric studies (DSC, DTA), microscopic observations(TEM/SAD, SEM, XRD, optical microscopy) and deformation tests (bending, tension). The glasstransition (Tg) and crystallization (Tx) temperatures with the corresponding supercooled liquidwindow ΔT = Tx – Tg have been determined for the mentioned rapid solidification techniques. GFAis found to be strongly dependent on specific ratio between the constituent alloying elements, witheffective element A containing mixture of the early transition elements A = (Ti,Zr,Hf) and effectiveelement B containing mixture of the late transition elements B = (Ni,Cu), respectively. We report achoice of the alloy composition, which is amorphous after fast cooling while recovers a reversibleB2 ↔ B19 ↔ B19' martensitic transformation sequence and demonstrates shape memory andsuperelastic properties (up to MS ~ 400 K, AF ~ 450 K in the bulk material versus MS ~ 250 K,AF ~ 350 K in the ribbon and strip states) after an adequate thermal treatment
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.59.113.pdf
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