Novel,liquid crystal formula to overcome LTPS LCD image sticking without adjustment of gamma code,optical, VHR and IS evaluation

In this article, novel n-FFS liquid crystal material from Slichem was used in order to elevate the anti-backlight long aging effect; a trace amount of free radical trap HALS-like additive was added, the principle of which can be expressed via Denisov cycle, confirmed by measuring the temporal VHR changes in test cells; three different resolution (FHD ~ QHD) models paired with N19 and N21 were selected for testing by comparing the actual panel. It is verified that the optimized material greatly improves the image sticking performance of the panel and keeping optical performance.     

增材制造技术在电机中的应用综述

增材制造技术(即3D打印)因具有高设计自由度、高材料利用率、高成形效率和精度等优势,逐渐成为高效轻质高功率密度电机设计与制造的研究热点。该文旨在对3D打印电机的性能及其应用作系统性综述。首先,对3D打印电机的发展脉络进行简要概括。其次,分别对3D打印铁心、磁钢、绕组,以及散热和机械支撑结构的研究现状进行总结,并与传统工艺加工的样件进行性能对比。随后,介绍了适用于增材制造的结构设计方法——拓扑优化。最后,根据目前的研究情况归纳了3D打印电机未来的发展趋势和面临的挑战。     

Applications of non-destructive testing techniques for post-process control of additively manufactured parts

This paper presents an overview on the principle of operation for post-process inspection non-destructive testing (NDT) techniques. The techniques include visual inspection, liquid penetrant testing, magnetic particle testing, eddy current testing, ultrasonic testing, and radiography. The applications of these NDT techniques in additive manufacturing (AM) and their suitability for defects detection of additively manufactured parts are reviewed. The sensitivity, and the advantages and disadvantages of each technique are evaluated. The types of defect, and the detectability of these defects by NDT techniques are assessed. The applicability of each NDT technique for different categories of AM process is discussed. The categories of AM are, namely, material extrusion, powder bed fusion, vat photopolymerisation, material jetting, binder jetting, sheet lamination, and directed energy deposition.     

纳米Fe_2O_3作为润滑油添加剂的摩擦磨损性能

采用烧结方法制备得到纳米α-Fe_2O_3,利用X射线衍射仪(XRD)和透射电镜(TEM)对样品进行了表征,研究了纳米α-Fe_2O_3作为液体石蜡添加剂的摩擦磨损性能。结果表明,添加纳米添加剂后,润滑油摩擦系数改变不明显,但磨损率显著降低。磨损率与纳米α-Fe_2O_3添加剂的表面积和添加量密切相关,当纳米材料的表面积为47m~2/g时磨损率最低,磨损率值降低为3.78×10~(-15) m~2/g;添加量为1.0wt%,润滑油磨损率最低。     

A linear algorithm for conformal 3D-to-flatness coordinates conversion

Data conversion from a 3D raster to spiral coordinates is the key function in the scanning process for Roll Powder Sintering (RPS) additive manufacturing technology. Conversion process is especially important, as it produces the basis for a processed object. There are many equations for such conformal transformation, but there is still room to improve the computation efficiency. This paper presents an efficient conversion algorithm, which processes 3D objects and linear transforming it into rolling ribbon. The new algorithm has several significant advantages over the old ones due to applying only one main linear equation. The program based on the linear algorithm is simpler, more compact and faster in comparison to other programs which use trigonometric, transcendental or other equations. The proposed algorithm has been developed and extensively tested on several parts of computer-aided design models for RPS processing.     

基于表面理论的温拌SBS改性沥青-集料体系的粘附性

采用躺滴法检测了掺加1.5%、3%的Sasobit和0.5%、1%的Evotherm 3G制备得到的温拌SBS改性沥青与蒸馏水、甘油和甲酰胺3种液体的接触角;基于表面自由能理论,对比了温拌SBS改性沥青在无水条件下的表面自由能和粘聚功以及在有水条件下的剥落功;同时,考察了温拌SBS改性沥青和石灰岩质集料的粘附功和配伍率。结果表明:采用躺滴法可以准确检测温拌SBS改性沥青与常用检测液体的接触角;以粘聚功、粘附功、剥落功、配伍率作为评价指标可用于表征温拌SBS改性沥青-集料体系的粘附性;温拌SBS改性沥青的表面自由能及其分量、粘聚功、配伍率随着Sasobit掺量的增大而减小,但随着Evotherm温拌剂掺量的增加而增大;水的参与降低了温拌剂对SBS改性沥青-集料体系粘附性影响的差异;Evotherm温拌剂有助于改善温拌SBS改性沥青的水敏感性,Sasobit温拌剂增加了温拌SBS改性沥青的水敏感性。     

Performance of porous asphalt mixture with various additives

The objective of this study is to evaluate the approaches to improve the durability and strength of the porous asphalt through laboratory testing. Porous asphalt specimens were prepared using three types of binders: high-viscosity binder (HVB), PG76-22 and PG70-22. Various additives: fibre, hydrated lime and DBS polymer, were utilised in the porous asphalt. Comprehensive laboratory tests, including strength test, binder draindown test, Cantabro abrasion test, moisture susceptibility test, rutting test, thermal stress restrained sample test, and permeability test, were conducted. It is found that HVB significantly improved the overall performance of the porous asphalt; DBS additive improved its high-temperature performance, but lowered the cracking resistance at low temperature as well as the durability; fibre enhanced its durability and anti-cracking performance at low temperature; hydrated lime improved its moisture stability while weakening its durability. It is concluded that HVB and polyester fibre should be used in all porous asphalt; DBS additive is good for porous asphalt in high-temperature areas, and hydrated lime can be added to porous asphalt in rainy areas.     

Additive Manufacturing of Titanium Alloys by Electron Beam Melting: A Review

Electron beam melting (EBM), as one of metal additive manufacturing technologies, is considered to be an innovative industrial production technology. Based on the layer‐wise manufacturing technique, as‐produced parts can be fabricated on a powder bed using the 3D computational design method. Because the melting process takes place in a vacuum environment, EBM technology can produce parts with higher densities compared to selective laser melting (SLM), particularly when titanium alloy is used. The ability to produce higher quality parts using EBM technology is making EBM more competitive. After briefly introducing the EBM process and the processing factors involved, this paper reviews recent progress in the processing, microstructure, and properties of titanium alloys and their composites manufactured by EBM. The paper describes significant positive progress in EBM of all types of titanium in terms of solid bulk and porous structures including Ti–6Al–4V and Ti–24Nb–4Zr–8Sn, with a focus on manufacturing using EBM and the resultant unique microstructure and service properties (mechanical properties, fatigue behaviors, and corrosion resistance properties) of EBM‐produced titanium alloys.

     

Microstructure and Processing of 3D Printed Tungsten Microlattices and Infiltrated W–Cu Composites

Tungsten is of industrial relevance due its outstanding intrinsic properties (e.g., highest melting‐point of all elements) and therefore difficult to 3D‐print by conventional methods. Here, tungsten micro‐lattices are produced by room‐temperature extrusion‐based 3D‐printing of an ink comprising WO₃–0.5%NiO submicron powders, followed by H₂‐reduction and Ni‐activated sintering. The green bodies underwent isotropic linear shrinkage of ≈50% during the thermal treatment resulting in micro‐lattices, with overall 35–60% open‐porosity, consisting of 95–100% dense W–0.5%Ni struts having ≈80–300 μm diameter. Ball‐milling the powders and inks reduced the sintering temperature needed to achieve full densification from 1400 to 1200 °C and enabled the ink to be extruded through finer nozzles (200 μm). Partial sintering of the struts is achieved when NiO is omitted from the ink, with submicron interconnected‐porosity of ≈34%. Several tungsten micro‐lattices are infiltrated with molten copper at 1300 °C under vacuum, resulting in dense, anisotropic W–Cu composites with 40–65% tungsten volume fraction. Partially sintered struts (containing nickel) with submicron open porosity are also infiltrated with Cu, resulting in co‐continuous W–Cu composites with wide W struts/Cu channels at the lattice scale (hundreds of micrometers), and fine W–Cu interpenetrating network at the strut scale (hundreds of nanometers) allowing for the design of anisotropic mechanical and electrical properties.

     

Effects of microstructure on fatigue crack propagation behavior in a bi-modal TC11 titanium alloy fabricated via laser additive manufacturing

In this study, the crack propagation behaviors in the equiaxed and equiaxed-columnar grain regions of a heat-treated laser additive manufacturing (LAM) TC11 alloy with a special bi-modal microstructure are investigated. The results indicate that the alloy presents a special bi-modal microstructure that comprises a fork-like primary α (α_p) phase surrounded by a secondary α colony (α_s) in the β phase matrix after the heat treatment is completed. The samples demonstrate a fast crack growth rate with larger da/dN values through the equiaxed grain sample versus across the equiaxed-columnar grain sample at low ΔK values (<13.8). The differences that are observed between the crack propagation behaviors (in the crack initiation stage) of the samples can be mostly attributed to the different size and morphology of the α_p lamellae and α_s colony within the grains in the equiaxed and columnar grain regions rather than the grain boundaries. The cracks prefer to grow along the α/β boundary with a smooth propagation route and a fast propagation rate in the equiaxed grain region, where the α_p and α clusters have a large size. However, in the columnar grain region, small and randomly distributed α_p lamellae generate a zigzag-shaped propagation path with a reduction in the da/dN value. Additionally, the change in the size of the α_p lamellae in the equiaxed grains (heat affected bands, HAB) is also observed to influence the propagation behavior of the crack during the crack initiation stage.