Material characterisation of copper based shape memory alloy

Superelastic property of SMA research

This project is funded by International Copper Association and aims to investigate the material characteristics of copper based superelastic alloys and compare against those of NiTi alloys. Having a deeper understanding will enable us to use these new materials in a more efficient way.

Static bending test:

The specimens used here have the dimensions of 12mm diameter and 125mm long, the specific rig was designed for this test. The test was carried out in a dynamic universal testing machine with 200kN capacity, the first step was to conduct a static monotonic loading test in the form of three-point bending, the photo below shows the specimen was tested with central stroke of 20mm. The maximum stroke at the centre point is about 24mm (two times of diameter).

bending

Dynamic bending test

The load-displacement curve displayed below is the the dynamic bending tests with different loading frequencies with 2% strain at outer side of the bars. It shows good recovery of superelastic behaviour of copper alloy.

SMA bending

This video was taken from the dynamic bending test, notice that the rig allowed the bar to rotate freely in this test.

More results will be posted soon….