Applying UCFTC and UPFR (ASTM Suggested Test Methods) On Different NiTi Shapes – Qualitative Comparison

Recently two (SMA related) new test methods were submitted to ASTM committee. The test methods were written and submitted as a combined effort of several industrial companies and government organizations. The main purpose of both methods is to enable standard test methods for actuation purposes of shape memory alloys. One method describes a Uniaxial Pre-strain and Free recovery (UPFR) test, while the other describes a Uniaxial Constant Force and Thermal Cycling (UCFTC) test.

Using a standard test method, one expects it to be general enough to cover a full diversity of the alloys and specimens tested. In particular, one may expect to apply the test on different shapes of the same alloy. In the current work, different shapes of high temperature (AF~100^oC) binary alloys were tested according to the suggested methods:  round dog-bones, flat sheet dog-bones and thin wires.

 The talk will cover the ability to apply the test methods on the different shapes using climate chamber based set-up. A qualitative comparison will be reported as well as some 'good workmanship' guidelines.