Materials Science Forum, Vol.394-3, 503-506, 2001
Preparation and characterization of Cu-based shape-memory thin wires obtained by in rotating water melt-spinning
Thin cylindrical wires have recently been prepared, directly from the melt, using the In Rotating Water Spinning Technique (INROWASP). Good results have been obtained for Cu-Al-Ni-based round wires with diameters ranging between 100 and 250 mum. Parameters of the process for obtaining regular wires have been approached. Meanwhile, those wires still present some surface irregularities. Acoustoplastic treatment has been applied on the as-cast wires to reduce these defects. These wires also exhibit good shape memory properties, both for uniaxial elongation and bending. The transformation temperatures of the as-prepared wires are depressed in relation to the bulk alloy, due to the finer microstructure of the wires. The temperature shift can be largely reduced by ageing at moderate temperatures (250 degreesC). When biased by a constant uniaxial tensile stress, an elongation up to 2% (at 70 MPa) is attained on cooling down the transformation, completely recovered on heating.