116 SMARQ Characterization Test 

A complete characterization test campaign for Arquimea’s SMA material (SMARQ) was planned and  completed. This test campaign included several tests in order to demonstrate the material capabilities to be used as the trigger element in space mechanisms. The following blocks of tests were carried out:   Strength characterization tests.  o Maximum Strength Test  o Reconditioning Force Test  o Superelastic Test  o Pull Force Performance Test   Transition temperatures tests.   Electrical activation tests.  o Electrical activation at 22ºC.  o Electrical activation at +125ºC.  o Electrical activation at -70ºC.   Lifetime tests at extreme thermal conditions.   o Lifetime at +125ºC.  o Lifetime at -70ºC.   Material behavior tests in vacuum conditions.   Assessment of material compatibility in space environment. 

Strength characterization tests  The scope of these tests is to obtain information about the force capabilities of the SMA actuator. A maximum strength test was carried out to determine the maximum applied stress the material can withstand without failure. A reconditioning force test has been performed in order to obtain information about the stress necessary to deform the SMA at its martensite phase and its behavior at different temperatures. An additional test, consisting of completing several load/unload cycles at different temperatures over the Austenite Finish Temperature (A f), in order to obtain the superelastic behavior of  the material has been completed. Finally, a test was included to obtain information about the pull force performance (maximum force) of the material, by blocking the actuator movement during the phase transformation and measuring the generated force. A Tensile Test machine with oven has been used for the strength characterization. The equipment is able to perform universal tension tests at a controlled temperature, in the range between ambient and 200ºC.  Transition temperatures test  This test has been carried out to obtain data about the material transition temperatures (As, Af, Ms and Mf) for different samples. The non-operation temperature and the relationship between the strain and the temperature during transformation were obtained with this test. Arquimea’s Actuators Test Bench was used to complete this test, as shown in Figure 5(a). The equipment is specifically designed to test smart materials and actuators, allowing the execution of complete thermo-electro-mechanical characterization of both, in its actual working configuration. The bench can also control the actuation of the device using an electronic driver and it has an oven that allows heating the sample to a specific temperature.  

Electrical activation tests  An activation test has been performed at different temperatures in the working range (-70ºC, +125ºC).  The material was loaded and externally activated by an electrical current. Measurements on strain, force, power consumption and generated force have been carried out for several samples, providing information to estimate the power consumption and the heating an d cooling times. Arquimea Actuators Test Bench of  Figure 4(a) was used to complete this test at temperatures between ambient and +125ºC.   For the cryogenic tests (-70ºC), a new test bench has been developed, as shown in Figure 4(b). A thermostatic bath was used to control the environment temperature of the sample at cryogenic temperatures down to -70ºC. The bench used a vertical measurement approach in order to allow the