In this study, we observed the effects of the processing-induced method on two different shape memory alloys (SMAs). First, we compare the transformation behavior of a martensitic NiTi SMA during thermal cycling using wide angle synchrotron radiation X-ray diffraction (WAXS). Based on the thermal cycling results, three observations about processing-induced SGAs as compared to SMAs can be seen: (1) retention of distorted austenite at high and low temperatures, (2) broadening of diffraction peaks in WAXS and disappearance of the thermal peaks in DSC measurements both due to induced strain, and (3) gradual increase in the amount of the martensitic phase. Second, we applied a processing-induced method to a FeMnAlCrNi alloy to examine the possibility of forming a strain glass alloy in an Fe-based system through sufficient dislocation formation via plastic deformation. This alloy was subjected to various percentages of cold work and characterized using scanning electron microscopy, differential scanning calorimetry, Vickers hardness, WAXS data. The results indicate with 50% thickness reduction, stress-free thermal cycling no longer exhibits a measurable phase transformation, suggesting the successful formation of strain glass alloy through sufficient dislocation. The results of this research contribute significantly to the advancement of strain glass alloys (SGAs), especially with respect to methods of creating induced disorder in an SMA to generate an SGA transition.

Shape memory alloys (SMAs) represent a revolutionary class of active materials that can spontaneously generate strain based on an environmental input, such as temperature or stress. SMAs can provide potential solutions to many of today's engineering problems due to their compact form, high energy densities, and multifunctional capabilities. While many applications in the biomedical, aerospace, automotive, and defense industries have already been investigated and realized for nickel-titanium (NiTi) based SMAs, the effects of controlling and designing the microstructure through processing (i.e. extreme cold working) have not been well understood. Current Ni-Ti based SMAs could be improved upon by increasing their work output, improving dimensional stability, preventing accidental actuation, and reducing strain localization. Additionally, there is a strong need to increase the transformation temperature above 115 °C, the current limit for NiTi and is especially important for aerospace applications. Previous research has shown that the addition on ternary elements such as Au, Hf, Pd, Pt, and Zr to NiTi can greatly increase these transformation temperatures. However, there are several limiting factors with these ternary additions such as increased cost, especially with Au, Pd, and Pt, as well as, difficulty in conventionally processing these alloys. Therefore, the main objectives of this research is to study how processing can alter the mechanical properties of NiTi and characterizing it using in situ synchrotron radiation x-ray diffraction (SR-XRD), understanding how we can process ternary SMAs (NiTiHf) by conventional means, and lastly how this processing alters precipitation characteristics and mechanical properties of these alloy systems.