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Formation and 3D architecture of Mg-NiTi interpenetrating-phase composite. (A) Schematic illustration of the fabrication process of the Mg-NiTi interpenetrating-phase composite by 3D printing of a Nitinol scaffold and subsequent pressureless infiltration of the scaffold with magnesium melt. SLM, selective laser melting. (B and C) XRT volume renderings of (B) the infiltrated composite and (C) Nitinol reinforcement in the form of rhombic dodecahedrons within the composite, obtained by filtering out the signal from the magnesium.
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It is of significance, but still remains a key challenge, to simultaneously enhance the strength and damping capacities in metals, as these two properties are often mutually exclusive. Here, we provide a multidesign strategy for defeating such a conflict by developing a Mg-NiTi composite with a bicontinuous interpenetrating-phase architecture throu...
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... objective resides not only in creating an unprecedented combination of properties in magnesium-based materials, which is appealing for structural and biomedical applications, but also in providing a new design concept and fabrication approaches that could be applicable to engineer other material systems for improved performance. Figure 1A illustrates the formation process of the Mg-NiTi interpenetrating-phase composite. The controlled architecting of the Nitinol reinforcement in the composite in the form of rhombic dodecahedrons was achieved through 3D printing of the Nitinol scaffold in line with the stereolithographic model. ...
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... in the composite in the form of rhombic dodecahedrons was achieved through 3D printing of the Nitinol scaffold in line with the stereolithographic model. A dense composite was generated by infiltration of the scaffold with the magnesium melt and subsequent solidification. X-ray tomography (XRT) volume renderings of the infiltrated composite (Fig. 1B) reveal a complete filling of the open pores in the scaffold by the magnesium. The spatial distribution of the Nitinol scaffold within the composite, as indicated by the filtered signal by excluding magnesium (Fig. 1C), demonstrates the bicontinuous nature of both constituent phases and their mutual interpenetration in three dimensions. ...
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... with the magnesium melt and subsequent solidification. X-ray tomography (XRT) volume renderings of the infiltrated composite (Fig. 1B) reveal a complete filling of the open pores in the scaffold by the magnesium. The spatial distribution of the Nitinol scaffold within the composite, as indicated by the filtered signal by excluding magnesium (Fig. 1C), demonstrates the bicontinuous nature of both constituent phases and their mutual interpenetration in three dimensions. The volume fraction of Nitinol in the composite was determined to be ~35.9% by XRT. The density of the composite was measured to be 3.21 g cm −3 ; as this conforms to the value calculated from the rule-of-mixtures, ...
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... A in Fig. 3C). At this stage, both constituents are plastically deformed and work hardened. The strong hardening behavior of the Nitinol leads to some recovery in the work-hardening rate of the composite. (For comparison, the deformation behavior of 3D printed dense Nitinol, using the same parameters as for the Nitinol scaffold, is shown in fig. S1.) After reaching the stress maximum of ~320 MPa (at a true stress of ~280 MPa), the true stress begins to decrease because of diminished work hardening and the evolution of irreversible damage (stage IV). The large deformation with true strain exceeding ~45% produces a complex stress state and constrained friction at the contact ...
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... the one hand, the Nitinol reinforcement exhibits markedly higher strengths than the magnesium matrix at ambient to elevated temperatures and can be notably work hardened during the large plastic deformation of its martensitic phase ( fig. S1) (16). This endows the composite with a high apparent work-hardening ability to realize a higher strength. As the temperature rises, the Nitinol skeleton plays an increasing role in carrying load in the composite, as its strength is less sensitive to temperature (Nitinol displays an insignificant decrease in strength up to 400°C) (29). ...
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... the composite exhibits an improved strength at ambient to elevated temperatures, exceeding that of a rule-of-mixtures estimate of its constituents, and displays excellent resistance to damage. These characteristics are accompanied by a synergetic enhancement of its damping capacity at differing strain amplitudes and a high-energy absorption efficiency, which are rarely attained in monolithic and 5-11, 13-15, 19, 20, 26, 27, 31-38). (A) Energy absorption per unit volume versus the maximum transmitted stress for the Mg-NiTi composite, magnesium alloys, and a wide range of other materials, specifically those commonly used for energy absorption (19,20,26,27,31,34,35,37,38). ...
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Citations
... Due to their continuous morphology, each phase can directly contribute to the final properties of the composite, allowing a combination of distinct properties [3,4]. Multiple combinations of materials to fabricate IPCs have already been studied in the literature [5][6][7][8][9][10][11][12]. Metal-ceramic IPCs have been studied for multiple applications such as orthopaedic applications [9], high-temperature environments, high cyclic fatigue scenarios, and braking systems [5,7]. ...
Triply Periodic Minimal Surface (TPMS)-based aluminium–alumina Interpenetrating Phase Composites (IPCs) manufactured through the combination of Additive Manufacturing (AM) and investment casting are explored in this study. Multiple alumina TPMS structures (Gyroid, Diamond, and Primitive) with different geometries and volume fractions were designed and fabricated using Digital Light Processing (DLP) AM technology. Afterwards, these ceramic structures were filled with an aluminium alloy via investment casting, uncovering an aluminium–alumina IPCs. A global characterization was performed, including ceramics shrinkage and mass loss; specimens’ morphology; chemical and crystalline characterization; density analysis and mechanical testing. Overall, DLP technology was found effective for producing these highly complex ceramic structures, with high surface quality. The sintered alumina structures presented a relative density of ca. 76.3% and a pseudo-ductile layer-by-layer failure behaviour, with Diamond-based TPMS exhibiting the highest compressive strength. Regarding the IPCs, the addition of aluminium significantly changed the compressive behaviour of the samples, presenting an energy absorption behaviour. The integration of the alumina phase into the aluminium alloy led to an improvement on the compressive offset stress of approximately 6% when compared to the aluminium alloy used. Diamond and Gyroid IPCs demonstrated similar mechanical behaviour and the highest mechanical performance.
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... Laser powder bed fusion (LPBF), the most famous metal additive manufacturing technique, has led a global manufacturing trend for the past decade based on its unique advantages for producing complexshaped metallic parts [1][2][3][4][5]. Using the LPBF technique, a three-dimensional (3D) product designed by computer-aided design (CAD) data can be directly printed by stacking a thin layer of metallic powder with a high-energy laser beam [6][7][8][9][10]. Based on the unique characteristic of LPBF, topology-optimized products can be produced for the weight-reduction, enhanced performance, and user-customization demanded by various industrial fields (e.g., aerospace, automobile, and medical/dental) [11][12][13]. ...
... 316 L SS, which is known to provide sufficient mechanical strength and corrosion resistance in water purification, was selected as the parent material. The experimental samples were prepared via SLM, which was characterized by high precision and high efficiency in the production of complex metallic structures [43][44][45][46][47][48] . SS-based microlattice metamaterials with different geometrical characteristics were successfully printed (Fig. 2a). ...
Continuous industrialization and other human activities have led to severe water quality deterioration by harmful pollutants. Achieving robust and high-throughput water purification is challenging due to the coupling between mechanical strength, mass transportation and catalytic efficiency. Here, a structure-function integrated system is developed by Douglas fir wood-inspired metamaterial catalysts featuring overlapping microlattices with bimodal pores to decouple the mechanical, transport and catalytic performances. The metamaterial catalyst is prepared by metal 3D printing (316 L stainless steel, mainly Fe) and electrochemically decorated with Co to further boost catalytic functionality. Combining the flexibility of 3D printing and theoretical simulation, the metamaterial catalyst demonstrates a wide range of mechanical-transport-catalysis capabilities while a 70% overlap rate has 3X more strength and surface area per unit volume, and 4X normalized reaction kinetics than those of traditional microlattices. This work demonstrates the rational and harmonious integration of structural and functional design in robust and high throughput water purification, and can inspire the development of various flow catalysts, flow batteries, and functional 3D-printed materials.
... Rosa et al. used selective laser melting via AM to craft lattice structures from 316L, revealing that these lattice structures exhibited damping capabilities superior to those of their bulk counterparts [38]. Similarly, Zhang et al. achieved a breakthrough by creating a 3D-printed Mg-NiTi interpenetrating-phase composite [39]. This composite was reinforced with NiTi scaffolding and a magnesium melt, concurrently enhancing both mechanical and damping properties. ...
... The emergence of multi-material additive manufacturing (=3D printing) techniques has addressed this limitation and has enabled us to closely emulate the abovementioned natural design paradigms. These techniques allow for the design of structures with interpenetrating soft and hard material phases, yielding composites with optimized properties [22][23][24][25][26] . In particular, controlling the type of the deposited material at the level of individual voxels makes Polyjet multi-material 3D printing highly suitable for the emulation of natural soft-hard interfaces [27][28][29] . ...
Durable interfacing of hard and soft materials is a major design challenge caused by the ensuing stress concentrations. In nature, soft-hard interfaces exhibit remarkable mechanical performance, with failures rarely happening at the interface. Here, we mimic the strategies observed in nature to design efficient soft-hard interfaces. We base our geometrical designs on triply periodic minimal surfaces (i.e., Octo, Diamond, and Gyroid), collagen-like triple helices, and randomly distributed particles. A combination of computational simulations and experimental techniques, including uniaxial tensile and quad-lap shear tests, are used to characterize the mechanical performance of the interfaces. Our analyses suggest that smooth interdigitated connections, compliant gradient transitions, and either decreasing or constraining strain concentrations lead to simultaneously strong and tough interfaces. We generate additional interfaces where the abovementioned toughening mechanisms work synergistically to create soft-hard interfaces with strengths approaching the upper achievable limit and enhancing toughness values by 50%, as compared to the control group.
... Several successful demonstrations have showcased the generative design of molecular-level structures utilizing sequence-based models and graph neural networks. [8][9][10][11][12][13] In the domain of macroscale material structure design, while the majority of studies have still focused on specific types of structures (e.g., regular lattices, [14][15][16][17][18] stochastic fiber networks, [19][20][21] and triply periodic minimal surfaces [22][23][24][25][26] using empirical or trial-and-error method to explore the much larger structural design space beyond these commonly studied structures, there are several attempts at two-dimensional generative designs. For example, variational autoencoders (VAEs) were introduced to provide optimal combinations of multiple representative structures of two-dimensional composite materials with the largest elastic properties. ...
Generative design for materials has recently gained significant attention due to the rapid evolution of generative deep learning models. There have been a few successful generative design demonstrations of molecular-level structures with the help of graph neural networks. However, in the realm of macroscale material structures, most of the works are targeting two-dimensional, ungoverned structure generations. Hindered by the complexity of 3D structures, it is hard to extract customized structures with multiple desired properties from a large, unexplored design space. Here we report a novel framework, a multi-objective driven Wasserstein generative adversarial network (WGAN), to implement inverse designs of 3D structures according to given geometrical, structural, and mechanical requirements. Our framework consists of a WGAN-based network that generates 3D structures possessing geometrical and structural features learned from the target dataset. Besides, multiple objectives are introduced to our framework for the control of mechanical property and isotropy of the structures. An accurate surrogate model is incorporated into the framework to perform efficient prediction on the properties of generated structures in training iterations. With multiple objectives combined by their weight and the 3D WGAN acting as a soft constraint to regulate features that are hard to define by the traditional method, our framework has proven to be capable of tuning the properties of the generated structures in multiple aspects while keeping the selected structural features. The feasibility of a small dataset and the scalability of the objectives of other properties make our work an effective approach to provide fast and automated structure designs for various functional materials.
... These composites, also known as interpenetrating phase composites (IPCs), consist of two or more phases of topologically continuous microstructures, each with its own unique set of material characteristics. In contrast to conventional composites, IPCs offer higher interconnectivity and interface-to-volume ratio with superior mechanical [1], [2] and physical properties [3]- [6]. ...
... However, IPCs with embedded architected NiTi cores have rarely been considered. In this context, Zhang et al. [3] carried out compressive testing of 3D architected Mg-NiTi IPCs that showed an excellent combination of mechanical properties compared to their constituent materials. Aydogmus [18] reported microstructural mechanical characteristics and phase transformation features in / 49.9 50.6 IPCs. ...
... Whereas, the reinforcement phase consists of conventional AlSi10Mg alloy for which the material data is taken from in-house experiments: Young's modulus is 76. 3 and Poisson's ratio is 0.33. Besides that, the reason for choosing AlSi10Mg for FE simulations of IPCs is its strong castability and the high strength-to-weight ratio [26]. ...
This work focuses on the computational investigation of 3D interpenetrating phase composites (IPCs) consisting of an architected shape memory alloy (SMA) microstructure embedded in an elastic-plastic second phase. The SMA functional phase consists of Nitinol (NiTi) for which the constitutive material behavior is simulated using a user-defined material subroutine (UMAT) in Abaqus finite element software. Beam-based and mathematically driven triply periodic minimal surfaces (TPMS) architectures are considered for the NiTi functional phase. IPC unit cells are identified and modeled considering idealized periodic boundary conditions (PBCs). The mechanical and functional properties of the unit cells are evaluated using volumetric homogenization. The effective mechanical response is evaluated and analyzed as a function of NiTi volume fraction considering various loading conditions. The results show that NiTi morphology significantly affects the elastic stiffness, which varies monotonically with NiTi content. Among the geometries considered for the NiTi cores, TPMS cores having a Schwarz Diamond topology resulted in the highest effective axial stiffness and bulk moduli, whereas TPMS IWP topologies resulted in the highest strain recovery.
... Infiltration casting is an effective means of preparing interpenetrating structures with in situ bonded interfaces, which is one of the favorable prerequisites for the formation of metallurgical bonding interface [31,32]. Pawlowski et al. [33] infiltrated liquid A356 into additively manufactured 316L lattice, and obtained A356/316L interpenetrating phase composites. ...
... The mechanical properties of the overall structure were significantly improved, while the mechanical characteristics of the porous materials were also maintained. Similarly, a Mg-NiTi composite with a bi-continuous interpenetrating-phase architecture was developed by infiltrating magnesium melt into three-dimensionally printed Nitinol scaffold [31]. The composite showed excellent mechanical properties with improved strength and exceptional energy absorption efficiency. ...
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... Functional heterogeneous structures (FHS) can be classified into "multi-material" and "multi-architecture" designs. Co-continuous composite lattice structures [18][19][20][21] are prime examples of multi-material heterogeneous structures. Supported by advanced multi-material 3D printing technologies, these composite structures, which are made from soft and hard materials according to a specific spatial pattern distribution [22], achieve unusual combinations of mechanical and physical properties, such as the decoupling of structural modulus and permeability. ...
... For example, ref. [14] proposed a method for creating an Mg-NiTi composite with a bicontinuous architecture of an interpenetrating heterogeneous medium. For this, a magnesium melt is infiltrated into a three-dimensionally printed nitinol frame, which allows for the creation of a composite with a unique combination of mechanical properties: increased strength at various temperatures, remarkable damage resistance, good damping ability at various amplitudes, and exceptional energy absorption efficiency. ...
... There are no detached microscopic grains behind the bar- Figure 14. Dependence of the maximum ballistic velocity on the mass of the incoming particle according to the Formula (14). Crosses represent the results of numerical calculations. ...
... Sci. 2023, 13, x FOR PEER REVIEW 19 of Dependence of the maximum ballistic velocity on the mass of the incoming particle according to the Formula(14). Crosses represent the results of numerical calculations. ...
A series of calculations has been conducted to study the high-speed interaction of space debris (SD) particles with screens of finite thickness. For the first time, taking into account the fracture effects, a numerical solution has been obtained for the problem of high-velocity interaction between SD particles and a volumetrically reinforced penetrating composite screen. The calculations were performed using the REACTOR 3D software package in a three-dimensional setup. To calibrate the material properties of homogeneous screens made of aluminum alloy A356, stainless steel 316L, and multilayer screens, methodical load calculations were carried out. The properties of materials have been verified based on experimental data through systematic calculations of the load on homogeneous screens made of aluminum alloy A356, stainless steel 316L, and multilayer screens comprising a combination of aluminum and steel plates. Several options for the numerical design of heterogeneous screens based on A356 and 316L were considered, including interpenetrating reinforcement with steel inclusions and a gradient distribution of steel throughout the thickness of an aluminum matrix. The study has revealed that the screens constructed as a two-layer composite of A356/316L, volumetrically reinforced composite screens, and heterogeneous screens with a direct gradient distribution of steel in the aluminum matrix provide protection for devices from both a single SD particle and streams of SD particles moving at speeds of up to 6 km/s. SD particles were modeled as spherical particles with a diameter of 1.9 mm made of the aluminum alloy Al2017-T4 with a mass of 10 mg.
