Download or read book Development of a Characterization Instrument for Thermomechanical Testing of Shape Memory Alloy Torque Actuators written by Gordon Fox and published by . This book was released on 2010 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis describes the design and ongoing construction of a torsional testing machine for shape memory alloy tubes and joints between these tubes and common structural materials. This machine is capable of finding the strength and stiffness of specimens, and in the future will be able to find how their properties vary with temperature. Actuators using shape memory alloys have the potential to be far smaller and lighter than actuators based on electric motors and hydraulic pumps. However, it is currently very difficult to incorporate shape memory alloys into such mechanisms due to their poor machinability. Hence, methods such as ultrasonic soldering and laser welding to join these to common materials such as steel and aluminum are being investigated. Ultrasonic soldering between nickel-titanium and aluminum was found to produce consistent joints with a shear strength of 5.3 ksi (37 MPa), which is strong enough to begin detwinning the material.