Mechanical anisotropy of shape-memory NiTi with two-dimensional networks of micro-channels

作者：Neurohr Anselm J; Dunand David C^*

来源：Acta Materialia, 2011, 59(11): 4616-4630.

DOI：10.1016/j.actamat.2011.04.007

• Porous material
• Nickel titanium
• Nitinol
• Shape memory
• Space-holder

Ni-51.4 at.% Ti (Nitinol) containing 24 and 34 vol.% orthogonally interweaving micro-channels with 350-400 mu m diameters was fabricated by a powder-metallurgy method. NiTi powder preforms containing steel wire meshes arranged in parallel layers were hot-pressed into NiTi/steel composites, from which the meshes were removed electrochemically, thereby producing micro-channels with tailorable morphology, fraction, and orientation. The compressive stiffness (15-35 GPa) and strength (420-780 MPa) can be controlled by the volume fraction and orientation of the micro-channels. Stiffness values are compared against analytical foam and composite models. A combination of elasticity, superelasticity, and the shape-memory effect allows for high strain recovery (93-95% of an applied compressive strain of 5%).

• 出版日期2011-6
• 单位西北大学