SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies最新文献

{"title":"SMST 2022 Basic Abstracts","authors":"","doi":"10.31399/asm.cp.smst2022fm03","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022fm03","url":null,"abstract":"\u0000 Listing of presentations at the SMST 2022 event that have only short abstracts. This listing does not include the presentations with extended abstracts presented elsewhere in this volume.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131254558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Phenomenological Model for the Anisotropic (Positive/Zero/Negative) Thermal Expansion in Shape Memory Alloys and its dependence on Phase Transformation and (Re)orientation of Martensite Variants","authors":"Mengqian Zhang, T. Baxevanis","doi":"10.31399/asm.cp.smst2022p0071","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0071","url":null,"abstract":"\u0000 Thermal expansion (TE) is inherent material property and a critical design parameter in applications in which dimensional stability and/or thermal fatigue resistance over a wide range of temperatures are required. Examples include high precision instruments, satellite antennas, and optical instruments. Metallic materials that undergo martensitic transformation have been recently shown to exhibit tailorable bulk TE due to the TE anisotropy of the low-crystallographic-symmetry martensite lattice. In these materials, the TE anisotropy of bulk polycrystals can be exploited through martensite variant \"orientation\" upon deformation processing. This work proposes a constitutive model for tailoring the anisotropic CTE in shape memory alloys (SMAs) during martensite variant texturing, which is validated against experimental data from NiTiPd. A description of the evolution of the anisotropic macroscopic thermal expansion (TE) tensor of bulk shape memory alloys (SMAs) during phase transformation and martensite (re)orientation is proposed. Given that the tailorability of the TE of SMAs originates from the crystallographic TE anisotropy of the low-crystallographic-symmetry martensite, the TE tensor is approximated by a function of the oriented martensite volume fraction and the orientation direction unitary tensor. The proposed model is validated against recent experiments on tailoring TE through martensite orientation in a NiTiPd high temperature SMA. In those experiments, the TE tensor component in the loading direction of NiTiPd in the martensite state was shown to decrease with increasing inelastic strain induced by uniaxial tensile loading. According to the model, the TE tensor components in the transverse to the loading directions decrease with increasing tensile inelastic strain.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128474342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How Do Advanced Micromachining Technologies Affect the Performance of Nitinol Medical Devices?","authors":"Lucas Bittigkoffer, Martin Baumann, Nils-Agne Feth","doi":"10.31399/asm.cp.smst2022p0016","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0016","url":null,"abstract":"\u0000 Advanced micromachining processes like laser micromachining, electric discharge machining (EDM) and milling are key processes when fabricating Nitinol medical devices. Unfortunately, each machining process alters the thermomechanical properties of Nitinol - especially around the processing zone. To judge how much this affects the functionality of Nitinol devices, precise knowledge about the micromachining processes applied is crucial. Performance of a medical device from a manufacturer point of view is governed by its geometry. Attainable geometries are linked to the respective machining technology. Lastly the process itself might be limited concerning surface roughness, contour accuracy, and aspect ratio. Ecological aspects include the achievable material removal rate (MRR, volume per time) and necessary post processes. In this work, the authors report on recent developments in the field of micromachining Nitinol, especially in which way the respective technology affects the properties and the design of medical components. A comparative analysis of micromachining technologies is presented.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125441786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue Testing of a New Generation Commercial Scale Ultra-Low Inclusion NiTi Alloy","authors":"A. Pequegnat, Walter Heitmann, Kyle E. Chapman","doi":"10.31399/asm.cp.smst2022p0045","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0045","url":null,"abstract":"\u0000 The effects of inclusions within a Nitinol alloy on the fatigue performance has been largely accepted by the Nitinol community. With significant reduction in size and density of non-metallic inclusions, the statistical probability of an inclusion being at the region of high stress and facilitating fatigue failure is much reduced. A new generation of commercial scale, ultra-low inclusion Nitinol material has been developed. The purpose of this study was to characterize this new alloy and demonstrate the improved fatigue performance. It was shown that a significant improvement fatigue performance can be realized with the new commercial scale ultra-low inclusion NiTi alloy. The results further suggest that inclusion size and density play a critical role in fatigue performance.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121720998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser Improved NiTi Surface for Biomedical Applications","authors":"J. Racek, P. Hauschwitz, R. Bičišťová, J. Brajer, Jaroslav Huyhn, P. Minárik","doi":"10.31399/asm.cp.smst2022p0107","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0107","url":null,"abstract":"\u0000 The surface structure of medical implants and their chemical state are extremely important for their lifetime and reliability. There are problems with the degradation of NiTi implants due to structural fatigue, localized tribo-corrosion, and inconsistent hemocompatibility. These issues potentially can be solved by surface texturing by controlled short laser pulse treatments with a multibeam approach explored in this study. One of the unique surface textures in nanoscale is represented by introducing laser induced periodic surface structures (LIPSS) into the implant surface. The LIPSS formation involves the excitation of surface plasmon polaritons and material surface reorganization. Ripples with periodicity less than 1 ?m along with the catalytic activity of oxide surface with \"rutile nanohairs\" can significantly reduce bacterial film adhesion while promoting surface endothelialization and hemocompatibility. The morphological texturing of the surface allows for tuning the wetting properties from extreme hydrophobicity to hydrophilicity. Reduction of friction and wear of material surfaces can be achieved by introducing textures that reduce the contact friction area. The geometry of the LIPSS and dimples maintains an adhesive film of liquid among moving parts. Short laser \"beam-shaped\" pulses were applied in this work to NiTi surfaces. The results indicate that LIPSS processing of NiTi surface with controlled height profiles and periodicity gives rise to chemisorbed hydrocarbon molecules on rutile oxide layer, which leads to super-hydrophobicity and a beneficial antibacterial effect. Ultrashort laser pulse micromachining does not affect the microstructure and martensitic phase transformation. The corrosion resistance of LIPSS textured NiTi surface is not degraded, and the process reduces friction area and maintains an adhesive film of liquid between the moving parts.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129695732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epitaxial NiTi Thin Films: A 3D Puzzle","authors":"K. Lünser, S. Schwabe, K. Nielsch, S. Fähler","doi":"10.31399/asm.cp.smst2022p0075","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0075","url":null,"abstract":"\u0000 NiTi films are widely used in micro applications due to their shape memory and superelasticity properties. When customizing the material for a specific miniature device, it is vital to understand the underlying martensitic microstructure, how it forms, and how it affects the shape memory effect. Up to now, most research on the martensitic microstructure in NiTi concentrates on NiTi bulk, but results derived from bulk materials are not always applicable for films as well. Even though polycrystalline NiTi films are widely available, these films contain grain boundaries, which hamper or even inhibit a scale bridging analysis of the martensitic microstructure. Therefore, the martensitic microstructure in NiTi films and its formation remains mostly unexplored. To improve NiTi for applications in miniature devices, it is thus helpful to study films without grain boundaries as model systems. In this study, the authors analyze single crystalline NiTi films grown by DC magnetron sputter deposition. These epitaxial films grow without large angle grain boundaries and make it possible to analyze the martensitic microstructure over several length scales. The work analyzed the martensitic microstructure and its nucleation with microscopy and X-ray methods and compared these measurements with orientation relationships calculated with the phenomenological theory of martensite. The results are the starting point to understand the formation of a hierarchical martensitic microstructure of NiTi in three dimensions.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131202643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Assessment of Physical and Mechanical Property Variability in a New Generation of Low Inclusion NiTi Alloy","authors":"W. Yin, F. Sczerzenie, R. Lafond","doi":"10.31399/asm.cp.smst2022p0091","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0091","url":null,"abstract":"\u0000 There is an increasing demand for high quality Nitinol medical devices and implants to accommodate to the rapid growth in the biomedical market. Extensive studies have confirmed the significant impact of micro-cleanliness of Nitinol on fatigue life. Ultra-clean Nitinol material is required for most critical medical applications such as cardiovascular and neurovascular devices for which integrity and durability are critical. This poses challenges for upstream manufacturers to consistently produce ultra-low inclusion Nitinol mill products. This work is a comprehensive to evaluate hot rolled bars and coils of a new commercial scale ultra-clean Nitinol alloy. The robustness of the alloy production process and stability of product properties was confirmed by examining a large number of mill products manufactured in different campaigns. Extensive characterization and multiple approaches of inclusion analysis demonstrated the consistent ultra-high cleanliness of the products.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126806054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuning Thermo-Mechanical Properties of Shape Memory Polymer Foams for Biomedical Applications","authors":"Sayyeda Marziya Hasan, T. Touchet, D. Maitland, Aishwarya Jayadeep","doi":"10.31399/asm.cp.smst2022p0026","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0026","url":null,"abstract":"\u0000 One application for shape memory polymers (SMPs) is a vessel occlusion plug for peripheral use. The SMP foam used for this device is a low-density material that actuates upon a heat stimulus from the patient's body temperature. The foam plug expands from a small, compressed geometry to a large, expanded plug that conforms to the shape of the cavity in which it is placed. This study explores a different approach to tuning foam thermal and morphological properties than what has been previously investigated. The authors tuned the morphological and thermo-physical properties of shape memory polyurethane/urea foams by adjusting the amount of water, a foaming additive, that was used during material fabrication. The results provide an additional tool for controlling SMP foam properties so that the material may be more suitable for a given application.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124798299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additively Manufactured High-Performance Elastocaloric Materials with Long Fatigue Life","authors":"Huilong Hou, E. Şimşek, Tao Ma, N. Johnson, Suxin Qian, Cheikh Cissé, Drew Stasak, Naila M. Al Hasan, Lin Zhou, Y. Hwang, R. Radermacher, V. Levitas, M. Kramer, M. Asle Zaeem, A. Stebner, R. Ott, Jun Cui, I. Takeuchi","doi":"10.31399/asm.cp.smst2022p0034","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0034","url":null,"abstract":"\u0000 Elastocaloric cooling, which exploits superelastic transitions of shape memory alloys to pump heat, has recently emerged as a frontrunner in alternative cooling technologies. Despite its intrinsic high efficiency, elastocaloric materials exhibit hysteresis associated with input work, a common attribute of caloric cooling materials. In this study, the authors created a Ni-Ti-based elastocaloric material by additive manufacturing nanocomposite materials using a laser directed-energy- deposition system. The material exhibited exceptional stability and unusual operational efficiency derived from the unique and intricate nanocomposite structures made by additive manufacturing. This demonstration shows the potential for using additive manufacturing to optimize caloric cooling by providing a highly desirable topology flexibility into materials components that serve as both refrigerants and heat exchangers.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"178 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123447618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SMA-Based Multi-Ring Self-Centering Damping Devices for Seismic Retrofit of Structures","authors":"M. Salehi, R. DesRoches, D. Hodgson, T. Kim Parnell","doi":"10.31399/asm.cp.smst2022p0009","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0009","url":null,"abstract":"\u0000 One of the effective methods to retrofit seismically vulnerable building structures is the use of supplemental energy dissipation devices. Such devices may decrease the seismic displacement and acceleration demands of the retrofitted structures, thereby mitigating damage to both structural and non-structural components. Due to the unique mechanical properties of superelastic (SE) Nitinol, such as high strength, significant elasticity, substantial energy absorption, and excellent fatigue resistance, various forms/shapes of SE Nitinol have been used to develop self-centering damping devices. SE Nitinol rings are particularly effective because they offer large ductility, can resist compression without buckling, allow multi-directional loading, and are cost-effective. Recently, an innovative class of self-centering damping devices incorporating SE Nitinol rings, termed SMA-based multi-ring (SBMR) devices, has been developed and numerically evaluated by the authors . Each SBMR damping device consist of at least one SE Nitinol ring and at least one supplemental energy dissipating (ED) ring. The rings are concentrically and tightly positioned inside one another such that they deform together. The ED rings are made of metals with high hysteretic damping capacity, such as mild steel or shape memory (SM) Nitinol. Under diametric deformation, both the SE and ED rings absorb energy, whereas the SE ring(s) are primarily intended to provide self-centering. Due to their shape, the SBMR devices may be installed in building frames through a variety of approaches, among which cross bracing is particularly efficient. This presentation evaluates the performance of SBMR devices through an extensive experimental study. This presentation discusses an extensive experimental study on four SBMR damping devices with different ring configurations. The initial test results for two single SM and SE Nitinol rings along with a double-ring device demonstrated the stability of the hysteretic responses of the proposed devices and their effectiveness in providing a balanced combination of damping and self-centering capabilities.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117029702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}