An Overview of ASTM Standard Test Methods for Shape Memory Alloy Actuation Materials

While there exists a broad range of potential applications for Shape Memory Alloy (SMA) actuators, their transition from prototype demonstration to commercialization and production use has been limited by the absence of accepted industry and regulatory testing and certification standards. To this end, a committee was formed with members from industry, government and academia to develop and publish standard test methods that are specifically intended to measure SMA actuation properties. The committee was organized within the Aviation Vehicle Systems Institute (AVSI). In 2017 two standard test methods were published by ASTM as E3097 – “Standard Test Method for Uniaxial Constant Force Thermal Cycling (UCFTC)” and E3098 – “Standard Test Method for Uniaxial Pre-strain and Free Recovery (UPFR)”. Since their release both standards have been subjected to ruggedness testing to identify test parameters that could impact the results of the test method. An ASTM Inter-Laboratory Study (ILS) to assess the precision of both test methods is underway. In addition to the recently published ASTM standards, there is a recognized need for a test method that defines and evaluates dimensional stability and the evolution of actuation properties during repeated UCFTC. Also, the need to extend the applicability of E3097 to torsional SMA actuators has been identified. With this in mind, test methods for thermomechanical cycling and torsion testing have been proposed to ASTM. This presentation will provide an overview of the published and recently proposed standard test methods, results from the ruggedness testing and an update on the progress of the ILS.