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Additive manufacturing (AM), also known as 3D printing, has greatly promoted the development of lattice structures with complex configurations. However, these lattice structures usually consist of periodically arranged nodes and struts. Here, inspired by the three-dimensional crystalline microstructure of selective laser melted (SLM) Al–Si alloy, a type of novel cellular structure with irregular nodes and struts was designed and fabricated by the SLM process with Al–Si alloy powder. The as-fabricated cellular structures were multi-scale materials from nano- to macro-scale. Electron backscatter diffraction (EBSD) analysis revealed that compared with the edge region, the central region of the struts had larger grain size, dominant (001) grain orientation, and worse toughness. Most importantly, compared with the regular lattice structures, the novel cellular structures brought about maximum 32.8% and 38.3% improvement in volumetric energy absorption W v and specific energy absorption W s , respectively. Furthermore, the finite element simulation was employed to reveal the stress distribution and energy absorption mechanism of cellular components during compression. Finally, the different fracture modes between the edge and central regions of the struts were investigated. The Al–Si crystalline microstructure inspired cellular structures have potential applications in biomaterials, vibration and thermal insulation. [ABSTRACT FROM AUTHOR]

Abstract: The influence of Y on microstructure and mechanical properties of as-cast Mg–5Li–3Al–2Zn alloy was investigated. The results show that the phase compositions of Mg–5Li–3Al–2Zn consist of α-Mg and AlLi phases. Adding Y to the alloy results in the formation of Al2Y compound and facilitates grain refinement. The addition of 0.8wt.% Y produces the smallest grain size. The tensile tests performed at room temperature show that the additions of Y can improve the mechanical properties of the alloy; the tensile strength and ductility reach peak values when the Y additions are 0.8wt.% and 1.2wt.%, respectively. The mechanisms of improvement are related to grain refinement and compound strengthening effects. [Copyright &y& Elsevier]

Abstract: As-cast Mg–5Li–3Al–2Zn–xRE (x =0–2.5wt.%) alloys were prepared under the ambient of pure argon, and the effects of Ce-rich rare earths (RE) and heat treatment on the microstructure and mechanical properties of Mg–Li–Al–Zn-based alloy were investigated. The results show that the main phase compositions of Mg–5Li–3Al–2Zn (LAZ532) alloy consist of α-Mg and AlLi. With the addition of RE, Al-RE precipitate forms, and increases gradually, whereas AlLi phase decreases. The room temperature tensile test reveals that the addition of RE could clearly improves the mechanical properties of alloys which are further improved after heat treatment. In more detail, excellent tensile strength and ductility are obtained in 1.5wt.% RE containing alloy in as-cast state. After heat treatment, the 1.0wt.% RE containing alloy attains superior tensile strength. The differences in tensile strength are related to the morphology, distribution of second phases and solid–solution strengthening in different alloy systems. In addition, the fracture pattern of the alloy is predominantly brittle cleavage and tends to be quasi-cleavage with RE addition. [Copyright &y& Elsevier]

In current work, we have used fiber laser welding (FLW) technology to manufacturing the Ti–6Al–4V (TC4) and Inconel 718 (IN718) bimetallic structure and to prevent the formation of brittle phases via Cu/Ta multi-interlayer. The results of this study showed that Cu/Ta multi-interlayer was very effective in preventing the formation of continuous brittle intermetallic layers of Ti–Ni and Ti–Cu. The good metallurgical bonds were presented at these interfaces between TC4 and IN718. As a result, the joints with gradational structure, i.e. TC4| (α+β Ti, Ta) ss | (β Ti, Ta) ss | Ta(s, s)+ (Cu(s, s)+ Ta(s, s)+ Ti 3 Ni 4)| Cu(s, s)+ (Cu(s, s)+ Ta(s, s))| Ni(Ta, Fe, Cr) ss | IN718 can be formed, which can contribute high tensile strength of joints with the value of 396 MPa. •In this paper, we use a new Cu/Ta multi-interlayer layer for fiber laser welding TC4 and IN 718. •The formation of continuous brittle intermetallic layers of Ti–Ni and Ti–Cu is effectively prevented. The tensile strength of the bimetallic structure with the Cu/Ta multi-interlayer was 396 MPa, which reached that of the 42.6% and 45.8% of the tensile strength of TC4and IN718, respectively. •In the present work, defect-free, dissimilar FLW of the bimetallic structure was successfully achieved by using Cu/Ta multi-interlayer. The typical microstructure of joint is TC4| (α+β Ti, Ta)ss| (β Ti, Ta)ss| Ta(s, s)+ (Cu(s, s)+ Ta(s, s)+ Ti3Ni4)| Cu(s, s)+ (Cu(s, s)+ Ta(s, s))| Ni(Ta, Fe, Cr)ss| IN718. [ABSTRACT FROM AUTHOR]

Abstract: Superlight alloys, including Mg–8Li–1Al, Mg–8Li–1Zn and Mg–8Li–1Al–1Zn, were prepared using vacuum induction melting furnace. Microstructures and phases of the alloys were studied with optical microscope and X-ray diffraction. Mechanical properties of these alloys were measured with tensile tester. The results of tensile tests show that, the as-rolled Mg–8Li–1Al alloy with a thickness of 0.16mm has the highest tensile strength (313.9MPa). The as-extruded Mg–8Li–1Zn alloy with a thickness of 3mm has the maximum elongation (44%). The as-rolled Mg–8Li–1Al–1Zn alloy with a thickness of 0.18mm has both high tensile strength and high elongation (233.38MPa and 9.2%, respectively). [Copyright &y& Elsevier]

Silicon-based anode for lithium-ion batteries (LIBs) has attracted much attention due to its high theoretical capacity, low operating potential and abundant resources. However, the large volume expansion/shrink during the lithiation/delithiation process induces extreme damage to the electrode microstructure. The resulting failure of electrical contact between silicon and current collector will severely deteriorate the cycling stability. Herein, a three-dimensional nano-Si/N-doped carbon network was obtained by a facile approach with NaCl templates. The N-doped carbon network not only significantly improves the electronic conductivity, but also ensures a valid electrode microstructure through a highly elastic carbon framework. Additionally, a two-dimensional nano-Si/N-doped carbon sheet was prepared without NaCl templates, revealing the boosting action of NaCl templates in the microstructure adjustment from low dimension to spatial crosslinking. The optimal three-dimensional nano-Si/N-doped carbon composite can deliver a high specific capacity of 1396 mAh g−1 with a capacity retention of 84.3% after 100 cycles at 200 mA g−1. This study provides effective guidance for novel Si-based anode design to achieve high-energy LIBs with excellent cycling stability. Image 1 [ABSTRACT FROM AUTHOR]