Roadmap on inorganic perovskites for energy applications

Authors thank EPSRC (EP/P007821/1) and Low Emissions Resources Global for support.Inorganic perovskites exhibit many important physical properties such as ferroelectricity, magnetoresistance and superconductivity as well their importance as Energy Materials. Many of the most important energy materials are inorganic perovskites and find application in batteries, fuel cells, photocatalysts, catalysis, thermoelectrics and solar thermal. In all these applications, perovskite oxides, or their derivatives offer highly competitive performance, often state of the art and so tend to dominate research into energy material. In the following sections, we review these functionalities in turn seeking to facilitate the interchange of ideas between domains. The potential for improvement is explored and we highlight the importance of both detailed modelling and in situ and operando studies in taking these materials forward.Publisher PDFPeer reviewe

A Review on Ultrafast-Laser Power Bed Fusion Technology

Additive manufacturing of metals by employing continuous wave and short pulse lasers completely changes the way of modern industrial production. But the ultrafast laser has the superiority to short pulse laser and continuous wave laser in additive manufacturing. It has higher peak power, small thermal effect, high machining accuracy and low damage threshold. It can effectively perform additive manufacturing for special materials and improve the mechanical properties of parts. This article reviews the mechanism of the interaction between ultrafast laser and metal materials to rule the manufacturing processes. The current application of ultrafast laser on forming and manufacturing special materials, including refractory metals, transparent materials, composite materials and high thermal conductivity materials are also discussed. Among the review, the shortcomings and challenges of the current experimental methods are discussed as well. Finally, suggestions are provided for the industrial application of ultrashort pulse laser in the field of additive manufacturing in the future

A Review on Ultrafast-Laser Power Bed Fusion Technology

Additive manufacturing of metals by employing continuous wave and short pulse lasers completely changes the way of modern industrial production. But the ultrafast laser has the superiority to short pulse laser and continuous wave laser in additive manufacturing. It has higher peak power, small thermal effect, high machining accuracy and low damage threshold. It can effectively perform additive manufacturing for special materials and improve the mechanical properties of parts. This article reviews the mechanism of the interaction between ultrafast laser and metal materials to rule the manufacturing processes. The current application of ultrafast laser on forming and manufacturing special materials, including refractory metals, transparent materials, composite materials and high thermal conductivity materials are also discussed. Among the review, the shortcomings and challenges of the current experimental methods are discussed as well. Finally, suggestions are provided for the industrial application of ultrashort pulse laser in the field of additive manufacturing in the future

Synchronous Shot Peening Applied on HVOF for Improvement on Wear Resistance of Fe-based Amorphous Coating

Shot peening was used synchronously to improve Fe-based amorphous coating performance by delivering ZrO2 ceramic particles into a low-temperature region of a flame during the high velocity oxygen flame (HVOF) spray process. The coating became denser, and its hardness became higher via the new process. Moreover, the compressive residual stress was induced by shot peening. The results from the dry friction test indicated that the coating’s wear resistance was enhanced obviously. The wear mechanism of coatings with and without shot peening is an abrasive wear combined with an oxidation wear at wear test conditions of a low load and a low frequency. The coating with the best wear resistance did not have the strongest microhardness but had the highest compressive residual stress. The compressive residual stress had a significant positive influence on the wear resistance at a low frequency, while its effect is weakened at a high frequency

Different-Shaped Ultrafine MoNbTaW HEA Powders Prepared via Mechanical Alloying

Different-shaped ultrafine MoNbTaW high-entropy alloy powders were firstly prepared by a convenient mechanical alloying method. The phase composition and microstructure of the powders were characterized. The powders are ultrafine with nano-sized grains and a good homogeneous microstructure. All the powders have a single body-centered cubic solid solution phase and form the high-entropy alloy during mechanical alloying. These powders with different shapes are quite attractive for developing high-performance MoNbTaW high-entropy alloy bulk and coatings combined with a following sintering, spraying, or additive manufacturing technique

Reversible bubble transfer on a bioinspired tridirectionally anisotropic lubricant-infused surface

Underwater bubble transfers on functional surfaces with special wettability have important research value for many fields such as water purification, gas-evolving electrochemistry, heterogeneous catalysis, etc. However, realizing multi-interface collaborated and multi-directional bubble transfers are still challenging. Herein, inspired by butterfly wings, pitcher plants, and rice leaves, we present a tridirectionally anisotropic lubricant-infused surface (TALIS) with micro–nano hierarchical step-like structures that are covered with silicone oil. The TALIS exhibits significant tridirectional anisotropy in terms of bubble sliding, specifically, the slippery property parallel to the grooves with an ultra-low bubble sliding angle (BSA) of ∼2°, and the unidirectional wettability perpendicular to the grooves with BSA difference of ∼48° result from the step-edge pinning effect. By adjusting the step height and width, TALISs with different tridirectionally anisotropic wettability and stable bubble-holding efficiency (∼0.4 mg/cm2) are obtained. In addition, horizontal and anti-buoyancy unidirectional bubble transfers are realized by collaborative squeezing of two face-to-face TALISs. By adjusting the distance between the two TALISs, bubbles can be reversibly transferred between the two interfaces by multi-interfaces collaboration. This work opens a new avenue to understand the bubble behaviors on functional interfaces with anisotropic wettability and provides a method to realize controllable bubble transfer on multi directions

Biomechanical study of femoral neck system for young patients with nonanatomically reduced femoral neck fractures: a finite element

Abstract Background A consensus regarding the optimal approach for treating femoral neck fractures is lacking. We aimed to investigate the biomechanical outcomes of Femoral Neck System (FNS) internal fixation components in the treatment of nonanatomically reduced femoral neck fractures. Method We constructed two types of femoral neck fractures of the Pauwels classification with angles of 30° and 50°, and three models of anatomic reduction, positive buttress reduction and negative buttress reduction were constructed. Subgroups of 1 to 4 mm were divided according to the distance of displacement in the positive buttress reduction and negative buttress reduction models. The von Mises stress and displacements of the femur and FNS internal fixation components were measured for each fracture group under 2100-N axial loads. Results When the Pauwels angle was 30°, the positive 1-mm and 2-mm models had lower FNS stress than the negative buttress model. The positive 3- and 4-mm models showed FNS stress similar to that of the negative buttress model. But the four positive buttress models had similar stresses on the femur as the negative buttress model. When the Pauwels angle was 50°, the four positive buttress models had higher FNS stress than the negative buttress model. Three positive buttress models (2 mm, 3 and 4 mm) resulted in lower stress of the femur than the negative buttress model, though the 1-mm model did not. When the Pauwels angle was 30°, the positive buttress model had a lower displacement of the FNS than the negative buttress model and a similar displacement of the femur with the negative buttress model. When the Pauwels angle was 50°, the positive buttress model had a higher displacement of the FNS and femur than the negative buttress model. Our study also showed that the von Mises stress and displacement of the internal fixation and the femur increased as the fracture angle increased. Conclusion From the perspective of biomechanics, when the Pauwels angle was 30°, positive buttress was more stable to negative buttress. However, when the Pauwels angle was 50°, this advantage weakens. In our opinion, the clinical efficacy of FNS internal fixation with positive buttress may be related to the fracture angle, neck-shaft angle and alignment in the lateral view. This result needs verification in further clinical studies

Microstructure and Performance of Fe₅₀Mn₃₀Cr₁₀Ni₁₀ High-Entropy Alloy Produced by High-Efficiency and Low-Cost Wire Arc Additive Manufacturing

High-entropy alloys exhibiting superior properties have great potential applications in various fields. The ability to achieve efficient and economical production of large size and complex structures of high-entropy alloy is of great significance to promoting its engineering application. Additive manufacturing is the key method to produce the complex component; however, the current trend in additive manufacturing of high-entropy alloys focuses on laser additive manufacturing, which is expensive and time-consuming. Herein, we developed a wire arc additive manufacturing (WAAM) method with high-efficiency and a low-cost Fe50Mn30Cr10Ni10 high-entropy alloy was successfully produced. The as-produced alloy was composed of face-centered cubic (FCC) phase with minor σ phase. Its microstructure mainly exhibited dendritic and cytosolic dendritic crystals. Mechanical strength of the additive manufactured alloy reached about 448 MPa with a high fracture elongation up to 80%. The additive manufactured alloy had good corrosion resistance with a protecting layer formed on the surface after corrosion testing, which was much better than 45 steel. Additionally, the frictional performance of the additive manufactured alloy was characterized against the grinding parts of steel and Al2O3 balls, and the corresponding friction mechanism was discussed

Microstructure and Performance of Fe50Mn30Cr10Ni10 High-Entropy Alloy Produced by High-Efficiency and Low-Cost Wire Arc Additive Manufacturing

High-entropy alloys exhibiting superior properties have great potential applications in various fields. The ability to achieve efficient and economical production of large size and complex structures of high-entropy alloy is of great significance to promoting its engineering application. Additive manufacturing is the key method to produce the complex component; however, the current trend in additive manufacturing of high-entropy alloys focuses on laser additive manufacturing, which is expensive and time-consuming. Herein, we developed a wire arc additive manufacturing (WAAM) method with high-efficiency and a low-cost Fe50Mn30Cr10Ni10 high-entropy alloy was successfully produced. The as-produced alloy was composed of face-centered cubic (FCC) phase with minor σ phase. Its microstructure mainly exhibited dendritic and cytosolic dendritic crystals. Mechanical strength of the additive manufactured alloy reached about 448 MPa with a high fracture elongation up to 80%. The additive manufactured alloy had good corrosion resistance with a protecting layer formed on the surface after corrosion testing, which was much better than 45 steel. Additionally, the frictional performance of the additive manufactured alloy was characterized against the grinding parts of steel and Al2O3 balls, and the corresponding friction mechanism was discussed