Skip Nav Destination
Close Modal
Update search
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
NARROW
Date
Availability
1-13 of 13
Additive Manufacturing of Shape Memory Alloys
Close
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
Sort by
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 1-2, May 6–10, 2024,
Abstract
View Paper
PDF
Most research to date in the field of L-PBF of nitinol has been with near equiatomic nickel-titanium binary pre-alloyed powders. Significant understanding over the last 10 years has been gained in relation to aspects such as microstructural evolution, control of elemental composition, phase transformation behaviour, control of defects and mechanical properties. Challenges with the use of pre-alloyed nitinol powders include expense and time constraints in producing new blends. Elemental blending with in-situ alloying of nickel, titanium and other constituents at the point of additive manufacture offers the opportunity to significantly accelerate the pace of research of nitinol material and part geometry design. Other potential advantages of elementally blended over pre-alloyed powders include reduced process costs, energy savings, and improved control over final part macroscopic properties as well as local microscopic composition and properties. The relationship between elemental and pre-alloyed powder characteristics, the nitinol L-PBF process parameters and the resulting melt homogeneity has not previously been examined. This paper addresses this gap by examining, for in-situ alloyed nitinol, the relationship between laser power, scanning speed, powder properties and the resulting solidification track characteristics, and comparing results to those from pre-alloyed powder.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 3-4, May 6–10, 2024,
Abstract
View Paper
PDF
The properties of nitinol, an alloy of nickel and titanium, include its good biocompatibility, corrosion resistance, damping capacity, fatigue strength, superelasticity, and shape memory characteristics. With other conventional methods, it has been challenging to achieve high precision and accuracy of the produced parts; however, laser powder bed fusion (L-PBF) has provided a useful new route for the processing of nitinol. While L-PBF offers many advantages, it also has drawbacks, including the potential for the formation of different phases and residual stress during rapid solidification. Post L-PBF heat treatment conditions aid in the generation of targeted stable phases. As reported by Lee et. al., the mechanical properties and transformation temperatures of the manufactured nitinol samples were largely influenced by the heat treatment. Fan et. al. showed an increase in the transformation temperatures by increasing the heat treatment temperatures after a solution heat treatment. Heat treatments that help in achieving the desired properties are two-step heat treatment processes. This study investigates the feasibility of applying a single-step solution heat treatment to Ni-rich nitinol and reports its effects on density, transformation temperatures, microstructures and microhardness for intended applications.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 5-6, May 6–10, 2024,
Abstract
View Paper
PDF
With the advancing progress in AM, there is a growing emphasis on powder manufacturing for reliable AM-built parts. Atomization technologies are well established for metal powder preparation, dominating the market for laser powder bed fusion (LPBF). They allow producing powders from a variety of metallic materials with high purity, adequate particles size distribution and without satellites.
Proceedings Papers
Unlocking Insights from In-Situ Meltpool Monitoring Data for Additively Manufactured NiTi Components
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 7-8, May 6–10, 2024,
Abstract
View Paper
PDF
The processing of Ni 50 Ti 50 (at.%) alloy via powder bed fusion using a laser beam (PBF-LB) technique has been reported to significantly alter the atomic percentage of Ni in the final NiTi part when compared to the feedstock composition, and the ensuing variations in the phase characteristics and transformation temperatures. Residual stresses are also another challenge in the PBF-LB processing of NiTi. These PBF-LB challenges stem from the choice of laser scanning strategy, and process parameter selection typically defined by volumetric energy density (VED). Heat treatment also plays a crucial role in releasing residual stresses and effectively adjusting or tuning the final properties of as-built NiTi components.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 9-10, May 6–10, 2024,
Abstract
View Paper
PDF
Due to the unique characteristics of nitinol (NiTi) such as shape memory and super-elasticity, it is widely utilized in various industries, particularly in aerospace and biomedical applications. Additive manufacturing technology can provide the accurate dimensioning of NiTi components, even for those with intricate and complex geometries. However, the presence of residual stresses poses a significant concern from additive manufacturing. These residual stresses can adversely impact the structural integrity and performance of the manufactured parts, necessitating careful consideration and management. This study delves into a distinctive approach for predicting residual stresses within additive manufactured NiTi components, employing a simple, non-destructive, and cost-efficient method that integrates beam mechanics equations with finite element analysis (FEA). This work aimed to develop a rapid and accurate method for measuring the residual stress from additively manufactured nitinol beams which will be validated via established techniques such as hole-drilling, XRD and/or neutron diffraction.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 11-12, May 6–10, 2024,
Abstract
View Paper
PDF
NiTi shows a very promising combination of properties among different shape memory alloys. However, machining NiTi is a challenging task, making the manufacturing of complex geometries hard to nearly impossible using conventional manufacturing routes. As a result, the material’s full potential of the material has not been harnessed. The pseudoelastic properties of bulk NiTi are restricted to an 8 % strain. Additive manufacturing of NiTi using laser powder bed fusion (LPBF) has been demonstrated as a successful alternative production route, capable of exhibiting pseudoelastic behavior even in the as-built state. Existing literature has shown that modifications of the processing parameters can change the properties of Ni-rich NiTi significantly, which can be utilized intentionally to control the pseudoelastic properties in LPBF-manufactured NiTi. The fabrication of porous and lattice structures using LPBF allows to attain specific properties. This is achieved not only through the adjustment of the laser parameters and scanning pattern but also by enabling the creation of specifically tailored feature sizes and geometrical designs, such as unit cell design, the number and distribution of unit cells, and gradation. These geometrical structures go beyond the conventional unit cell designs (like the bcc unit cell), and when combined with the unique material behavior, they can result in extraordinary properties. It is possible to create a programmable material whose behavior can follow a logical description. The influence of lattice structure geometry and manufacturing parameters on the mechanical and functional performance will be discussed in the following. In addition, we present a structure whose stiffness behavior follows an if-then-else statement regarding to the effective strain and permits an effective strain exceeding 20 % without failure. The structure can be implemented in a planar clamping element which allows an adjustment to different shapes because of the high and low stiffness in different strain ranges.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 13-15, May 6–10, 2024,
Abstract
View Paper
PDF
Nickel-titanium offers a promising alternative to traditional actuation devices due to its shape memory effect (SME) large strain recovery, and damping capability. Shape memory alloy actuators, thereby, offer a low-shock alternative to traditional pyrotechnic release devices used in spacecraft and satellites as well as energy-absorption components such as spacecraft landing systems. Additive manufacturing (AM) allows the production of complex geometries benefiting from their lightweight and compact nature. A prime example is lattice structures, with a geometrically defined porous structures featuring a repeating unit cell pattern or patterns in space. Beyond being lightweight, these structures offer high specific strength, excellent shock absorption, heat dissipation, and biocompatibility. By examining different process parameters, AM presents the possibility of tailoring nitinol’s properties while potentially removing the additional step of post-processing heat treatments conventionally required for shaping shape memory alloys. This approach has the potential to save time, cost, and energy.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 16-18, May 6–10, 2024,
Abstract
View Paper
PDF
Additive manufacturing (AM), also known as 3D printing, has created new possibilities for designing and producing innovative NiTi medical implants. This technology offers significant advantages over traditional manufacturing methods, including the ability to produce complex geometries tailored to individual patient anatomy, potentially leading to better surgical outcomes and faster recovery times. These capabilities facilitate the creation of implants that are not only more biocompatible but also capable of promoting better osseointegration and reducing the risk of implant rejection.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 19-20, May 6–10, 2024,
Abstract
View Paper
PDF
Advances in Additive Manufacturing using Shape Memory materials have found widespread use in medical, aerospace and automotive sectors. 4D Printed parts with shape memory and stimuli responsive materials can be programmed for transformation, actuation and self-assembly. This offers the potential to foster the development of specialized high- value products that can operate passively without an external power source and with fewer electromechanical components. To reach a high level of industrial maturity, standards are needed to accurately represent shape transformations to enable design engineers to accurately communicate the functional requirements for manufacturing; as well as for metrologists and test engineers to inspect for product quality control. However, a fundamental challenge exists: How do we ensure that the design, manufacturing and functional intent for 4D Printed parts are accurately and unambiguously communicated between stakeholders across the design, manufacturing, inspection and supply value chain? This paper proposes a new standard for technical product documentation, geometric product specification and engineering drawings within British Standard BS 8888. To illustrate how the proposed standard could be applied, a use-case with different shape transformation properties are considered in a workflow.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 21-22, May 6–10, 2024,
Abstract
View Paper
PDF
Active hybrid composites are gaining significance in various industrial and medical applications. These composites can include the integration of shape memory alloy (SMA) wires and fibre-reinforced plastics at material level and have the ability to undergo large deformations while activated. Typical applications are aerodynamic components such as car spoilers or wing profiles of an aircraft. Most applications often follow a partially integrated or modular shape memory alloy hybrid composite (SMAHC) design. In this paper, we pursue the approach of a fully integrated construction of an SMAHC. Therefore, we introduce two different designs of flexible interlayer of a 4D printed SMAHC by using the 3D stereolithography process. Achieving direct integration of SMA’s into plastic matrices requires the matrix material to possess adequate flexibility, as the SMA's thermal phase transformation process can accommodate elongation of up to 8%. Moreover, it is imperative to ensure that the process temperatures of the chosen manufacturing method remain below the austenite start temperature (As) to prevent inadvertent activation of the SMA during fabrication.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 23-24, May 6–10, 2024,
Abstract
View Paper
PDF
Shape memory alloys (SMA) are functional materials that are being applied in practically all industries, from aerospace, automotive, robotics and biomedical sectors, and at present the scientific and technologic communities of SMA are looking to get the advantages offered by the new processing technologies of additive manufacturing (AM). However, the use of AM to produce functional materials, like SMA, constitutes a real challenge because of the particularly well controlled microstructure required to exhibit the functional property of shape memory. Most of the efforts are being focused on AM of Ti-Ni alloys, but there is a growing interest in Cu-based SMA due to their good functional properties of shape memory and superelasticity, even at high temperature. In the present work, the design of the complete AM processing route, from powder atomization and using two different methods of AM, is developed and the finally obtained thermomechanical properties are compared to those obtained by classical powder metallurgy route, using exactly the same Cu-Al-Ni SMA powders.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 25-26, May 6–10, 2024,
Abstract
View Paper
PDF
Superelastic NiTi (Nitinol) alloy is a smart material applied in the biomedical sector for devices, such as stents, implants and orthodontic wires. Nevertheless, after surgery, one of the major causes of failure, which requires the explantation of the device, is linked to bacterial infections. Therefore, development of antibacterial materials becomes an important task in the biomedical field. In this light, the present study investigates the integration of pseudoelasticity of Nitinol withan antibacterial response for realizing advanced implantable devices.
Proceedings Papers
SMST2024, SMST 2024: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies, 27-28, May 6–10, 2024,
Abstract
View Paper
PDF
Additive manufacturing (AM) of Shape Memory Alloys (SMA) is an emerging technology that can open the route for numerous new applications in the fields of actuation, sensing, energy harvesting, and heat management. Currently, most AM processes of SMA rely on melting-based methods that locally melt the metallic feedstock of Ni-Ti. However, the repeated melting impairs the resulting microstructure, thus limiting the ability to undergo a reversible thermo-elastic martensitic transformation. Recent advances in sinter-based AM have the potential to facilitate the control over the final microstructure and properties of the printed SMA. Here, we present the production and characterization of Ni-Ti SMA produced via two sinter-based AM methods: 1. Lithography-based Metal Manufacturing (LMM), and 2. Moldjet, a unique modification of conventional metal injection molding.