This work details an investigation into the production of porous shape memory alloys (SMAs) via hot isostatic press (HIP) from prealloyed powders. HIPing is one of three main methods for producing porous SMAs, the other two are conventional sintering and selfpropagating hightemperature synthesis (SHS). Conventional sintering is characterized by its long processing time at near atmospheric pressure and samples made this way are limited in porosity range. The SHS method consists of preloading a chamber with elemental powders and then initiating an explosion at one end, which then propagates through the material in a very short time. HIPing provides a compromise between the two methods, requiring approximately 5 hours per cycle while operating in a very controlled environment. The HIPing method gives fine control of both temperature and pressure during the run which allows for the production of samples with varying porosity as well as for finetuning of the process for other characteristics. By starting with prealloyed powder, this study seeks to avoid the drawbacks while retaining the benefits of HIPing with elemental powders. In an extension of previous work with elemental powders, this study will apply the HIP method to a compact of prealloyed powders. It is hoped that the use of these powders will limit the formation of alternate phases as well as reducing oxidation formed during preparation. In addition, the nearspherical shape of the powders will encourage an even pore distribution. Processing techniques will be presented as well as a detailed investigation of the thermal and mechanical properties of the resulting material.

This book provides a systematic approach to realizing NiTi shape memory alloy actuation, and is aimed at science and engineering students who would like to develop a better understanding of the behaviors of SMAs, and learn to design, simulate, control, and fabricate these actuators in a systematic approach. Several innovative biomedical applications of SMAs are discussed. These include orthopedic, rehabilitation, assistive, cardiovascular, and surgery devices and tools. To this end unique actuation mechanisms are discussed. These include antagonistic bi-stable shape memory-superelastic actuation, shape memory spring actuation, and multi axial tension-torsion actuation. These actuation mechanisms open new possibilities for creating adaptive structures and biomedical devices by using SMAs.

This book showcases different processes of fabrication and processing applied to shape memory alloys. It provides details and collective information on working principles, process mechanisms, salient features, novel aspects, process capabilities, properties of material and unique applications of shape memory alloys. The recent progress on fabrication and processing are specially addressed in this book. It covers major topics of manufacturing such as machining, joining, welding and processing of shape memory alloys.

Ferromagnetic shape memory alloys (FSMA's) are known to produce large strains in the presence of magnetic fields. Amongst the FSMA's near stoichiometric Ni2MnGa alloys present copious conceivable applications such as actuators and sensors due to these large magnetic field induced strains (MFIS's). Albeit, the large MFIS's are often observed in single crystals; which are difficult to manufacture and possess limited ductility. Recent investigations of polycrystalline Ni-Mn-Ga foams are reported to exhibit comparable MFIS's to those reported for single crystals. Therefore the ability to increase the MFIS in Ni-Mn-Ga alloys is envisioned through the introduction of pores in the microstructure. However, the manufacturing is difficult for all the above-mentioned Ni-Mn-Ga materials. Moreover, current techniques lack the ability to manufacture complex geometries. Additive Manufacturing (AM) via binder jetting is a method for producing porous near net shaped components utilizing micrometer sized material. This research investigates an additive manufacturing route of producing functional net shaped parts from pre-alloyed magnetic shape memory Ni-Mn-Ga powders. Three types of Ni-Mn-Ga powders were used in this investigation: spark eroded in liquid nitrogen (LN2), spark eroded in liquid argon (LAr), and ball milled (BM). Additive manufacturing via powder bed binder jetting, also known as 3D printing (3DP) was used in this research due to the ability to control part porosity and the possibility to obtain complex shaped parts from Ni-Mn-Ga alloys. The fourth-dimension (4D) is created by the predictable change in 3D printed part configuration over time as the result of shape-memory functionality. Powder characterization techniques including packing density measurements, size distribution analysis, and binder saturation experiments were conducted on the powders to obtain optimized printing parameters, respectively. The optimum layer thickness and binder saturation range was determined as 80 - 110 μm, and 110 - 250 %, respectively. Binder jetting of Ni-Mn-Ga powders followed by curing and sintering proved successful in producing net shaped porous structures (spring-like, 3-D hierarchical lattice structures, etc.) with suitable mechanical strength. Parts with porosities between 24.08 % and 73.43 % (1.164 g/cm3 to 6.35 g/cm3) have been obtained by using powders with distinct morphologies. The printed and sintered Ni-Mn-Ga parts undergo reversible martensitic transformations during heating and cooling, which is a prerequisite for the shape memory effect. Thermo-magneto-mechanical trained 3D printed parts obtained from ball milled Ni-Mn-Ga powders showed reversible magnetic-field-induced strains (MFIS's) of up to 0.01%. Binder jetting additive manufacturing is a viable technology in solving the design issues of functional parts made of Ni-Mn-Ga magnetic shape-memory alloys (MSMA).

"Proceedings from the only conference on medical devices that brings together scientists and product, research, design and development engineers from around the globe to present the latest developments in materials, processes, product performance and new technologies for medical/dental devices." "This volume includes contributions from the world's foremost experts from academia, industry, and national laboratories involved in cardiac, vascular, neurological, and orthopaedic implants, dental devices, and surgical instrumentation/devices." "Materials addressed include biomedical alloys (stainless steels, titanium alloys, cobalt-chromium alloys, nickel-titanium alloys, noble and refractory metals) biopolymers, bioceramics, surface coatings, and nanomaterials." "Topics covered include: degradation, wear fracture, corrosion, processing, biomimetics, biocompatibility, bioelectric phenomena and electrode behavior, surface engineering, and cell-material interactions."--BOOK JACKET.