Fabrication and characterization of amorphous–crystalline TiNiCu melt-spun ribbons

• Published in: Journal of alloys and compounds 2013-11, Vol.577, p.S251-S254
• Main Authors: Shelyakov, A.V., Sitnikov, N.N., Menushenkov, A.P., Korneev, A.A., Rizakhanov, R.N., Sokolova, N.A.
• Format: Article
• Language: English
• Subjects: Alloys; Amorphous materials; Composite materials; Cooling rate; Crystal structure; Devices; Melt spinning; Microstructure; Phase transitions; Quenching; Rapid-solidification; Ribbons; Shape memory alloys; Tapes (metallic); Titanium base alloys
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.02.146

► Amorphous–crystalline ribbon as composite material with two-way shape memory effect. ► Ti–50Ni–25Cu (at.%) alloy ribbons are fabricated by the melt spinning technique. ► Thickness of crystalline layer of composite depends on cooling rate of the melt. ► Elemental composition does not change in the cross-section of ribbons. ► Laminated amorphous–crystalline composite can be used in micromechanical devices. This study reports on the development of a composite material, amorphous–crystalline TiNiCu alloy ribbons, exhibiting reversible shape memory effect. A Ti–25Ni–25Cu (at.%) alloy was fabricated by the melt spinning technique at different cooling rates in the form of a ribbon with a thickness of approximately 40μm. The samples were characterized by means of inverted metallographic and scanning electron microscopy techniques, energy dispersive X-ray analysis and microhardness measurements. The ribbons were mainly amorphous but had a crystalline surface layer with orthorhombic structure on one side. The thickness of the crystalline layer varied from 5 to 10μm depending on cooling rate of the melt. No elemental composition change was found in the cross-section of the ribbons. This laminated amorphous–crystalline composite material demonstrated two-way shape memory behavior without any additional thermomechanical treatments and can be used to create micromechanical devices.