Showing papers on "Whisker published in 2017"
TL;DR: In this paper, the authors present in situ environmental transmission electron microscopy (ETEM) observation of metallic lithium nucleation, growth and shrinkage in a liquid confining cell, where protrusions are seen to grow from their roots or surfaces, depending on the overpotential.
327 citations
TL;DR: Li et al. as mentioned in this paper developed a CaCO3 whisker modified ECC with local ingredients in China, which can potentially reinforce the ECC materials at microscopic level, and they conducted cube compressive and uniaxial tensile tests were conducted to investigate the influence of CaCO 3 whisker on ECC's mechanical properties.
63 citations
TL;DR: In this article, a novel aluminium borate whisker (ABOw)/Al 2 O 3 -SiO 2 aerogel composites were prepared by adding ABOw into an Al 2 O3 -Si O 2 solution using a quick gel and supercritical fluid drying method.
58 citations
TL;DR: In this paper, as-received and pre-coated SiC whiskers (SiC w )/SiC ceramics were prepared by phenolic resin molding and reaction sintering at 1650°C.
56 citations
TL;DR: In this article, a high strength lightweight mullite whisker network reinforced ceramic materials was successfully prepared by firing a bauxite - kaolin - coal fly ash mixture with additions of varying mixtures of feldspar - talcum - BaCO 3 - pyrolusite.
50 citations
TL;DR: In this article, the effect of MoO 3 catalyst on mullitization reaction and mullite morphology is investigated by XRD analysis and SEM observation, and the combined results from TG-DSC and XRD suggest that the formation of Al 2 (MoO 4 ) 3 delays the sublimation temperature of Mo O 3 from 600 to 800 °C.
48 citations
TL;DR: Graphene-coated tetrapod ZnO whisker (T-ZnO) hybrid is fabricated by chemical modification of TZNO with an aminosilane, covalent coating with graphene oxide (GO) sheets, and reduction of the GO component by UV irradiation or thermal annealing as mentioned in this paper.
Abstract: Graphene-coated tetrapod ZnO whisker (T-ZnO) hybrids are fabricated by chemical modification of T-ZnO with an aminosilane, covalent coating with graphene oxide (GO) sheets, and reduction of the GO component by UV irradiation or thermal annealing. Compared to the moderately reduced hybrid by UV irradiation, the thermally annealed hybrid at 1000 °C (TGO1000@T-ZnO) is highly efficient in improving both thermal and electrical conductivities of epoxy. A high thermal conductivity of 5.06 W/(m K) is achieved for the epoxy composite with 65 vol.% TGO1000@T-ZnO hybrid. The epoxy composite with 65 vol.% TGO1000@T-ZnO also exhibits a high electrical conductivity of 27.2 S/m due to the efficiently formed electrically conducting network with only ∼4 wt.% well-distributed TGO sheets that are coated on T-ZnO substrates. The excellent thermal and electrical conductivities are attributed to the efficient conductance pathways formed by the skeleton of ZnO whiskers and the enhanced phonon and electron transfers by TGO sheets.
44 citations
TL;DR: In this paper, a double-layer coating system consisting of MoSi2 ceramic reinforced with SiC whiskers and a MoSi 2-TaSi2-SiC ceramic coating reinforced with siC whisker was presented.
44 citations
TL;DR: In this article, the authors used Tetra-needle-like ZnO whiskers to improve the mechanical properties of oil-well cement composites, and also analyzed by means of scanning electron microscopy (SEM), mechanical testing, X-ray diffraction (XRD), Infrared spectrum analysis, thermal stability analysis and 29Si NMR analysis.
41 citations
TL;DR: In this article, the authors investigate the extent to which each of the 20 possible combinations of the six mechanical signals at the whisker base can uniquely determine 3D contact point location for four different whisker profiles (shapes): tapered with and without intrinsic curvature, and cylindri.
Abstract: Almost all mammals use their mystacial vibrissae (whiskers) as important tactile sensors There are no sensors along the length of a whisker: all sensing is performed by mechanoreceptors at the whisker base To use artificial whiskers as a sensing tool in robotics, it is essential to be able to determine the three-dimensional (3D) location at which a whisker has made contact with an object With the assumption of quasistatic, frictionless, single-point contact, previous work demonstrated that the 3D contact point can be uniquely determined if all six components of force and moment are measured at the whisker base, but these measurements require a six-axis load cell Here, we perform simulations to investigate the extent to which each of the 20 possible “triplet” combinations of the six mechanical signals at the whisker base uniquely determine 3D contact point location We perform this analysis for four different whisker profiles (shapes): tapered with and without intrinsic curvature, and cylindri
38 citations
TL;DR: In this paper, the Widmanstatten microstructure evolution of the composite and the TiB whiskers realignment effect during thermo-mechanical processing were investigated, and the mechanical properties of composite were measured.
TL;DR: In this paper, the effect of crystallinity of potassium titanate whisker on the tribological behavior was investigated, and the results revealed that the higher crystallinity whiskers was significant to form stable contact plateaus.
TL;DR: In this article, a new type of ceramic is developed based on tobermorite whiskers, in which aluminum replaces some of the original silicon atoms, and these whisker-reinforced ceramics are synthesized from coal fly ash through a dynamic hydrothermal method.
TL;DR: In this article, an Electron back-scatter diffraction (EBSD) was used for orientation mapping of Sn grains in a 4 gm thick Sn coating deposited on brass.
TL;DR: In this paper, tetrapod-shaped ZnO (T-ZnO) whiskers were filled into silicone oil to form a fluid system and the experimental results demonstrate that the thermal conductivity and viscosity of thermal greases depend strongly on the structures and volume fractions of ZnOs.
TL;DR: In this paper, a trace amount of rare earth rare earth Pr was added into 0.3Ag-0.7Cu low-Ag solders to enhance properties of solders.
Abstract: In this study, trace amount of rare earth Pr was added into Sn–0.3Ag–0.7Cu low-Ag solder to enhance properties of solders. Experimental results indicated that optimal amount of Pr addition (~0.06 wt%) can improve properties of wettability, shear force and ductility of Sn–0.3Ag–0.7Cu low-Ag solder. This is because that solder with optimal Pr addition not only had a refined microstructure but also owned a regular and thin interfacial IMC layer after soldering on Cu substrate. Meanwhile, we have explained the change of morphology and thickness of interfacial IMC layer after Pr addition based on Kim and Tu’s kinetic model of interfacial IMC growth. However, it was found excessive Pr addition led to the formation of PrSn3 phase, which was easy to be oxidized and became a great deterioration on the properties referred above. Besides, the fracture mode of solder joint also gradually changed from ductile fracture to cleavage fracture. Moreover, this oxidized PrSn3 became the birthplace of Sn whisker since it provided abundant supply of Sn sources and compressive stress for Sn whisker growth. By the in-situ observation of Sn whisker growth in 0.5 wt% Pr-doped solder joint, we obtained that the incubation period of Sn whisker is very short and its growth rate may have a great decrease with time extending. Besides, it was found after 1 day at room temperature, spindly and rod-like Sn whiskers also grew in 0.5 wt% Pr-doped solder joint besides dot-shaped Sn whisker that grew in 0.5 wt% Pr-doped solder matrix. We suggest this may be related with the extra compressive stress provided by interfacial IMC layer growth in 0.5 wt% Pr-doped solder joint.
TL;DR: In this article, the effects of TiC nanoparticle content, particle size and preparation process on the mechanical properties of hot pressed Al 2 O 3 -SiC w ceramic tool materials were investigated.
TL;DR: In this paper, the effect of whisker addition on the room-temperature mechanical properties of fine-grained alumina ceramics has been investigated and it was found that adding a whisker retards slightly the sinterability of alumina by hindering particle rearrangement.
TL;DR: In this paper, the effects of β-Si3N4w content and sintering parameters on the densification and tensile behavior of composites were investigated, and the results indicated that higher whisker content could improve composites to the maximum value of 312 MPa, which was 158 MPa higher than pure Al.
Abstract: Al matrix composites reinforced with β-Si3N4 whiskers (β-Si3N4w) were fabricated by hot pressing method. The microstructures showed that the whiskers were uniformly dispersed in the matrix and the Al/β-Si3N4 interface was well bonded without interface reaction. Effects of β-Si3N4w content and sintering parameters on the densification and tensile behavior of composites were investigated. The results indicated that β-Si3N4w could both enhance the ultimate tensile strength (UTS) and maintain the ductility of Al matrix when the whisker content was 5 vol%, corresponding to an elongation at break and an UTS of 21.2% and 239 MPa, respectively. However, higher whisker content could improve UTS of composites to the maximum value of 312 MPa, which was 158 MPa higher than pure Al, while reducing elongation of composites. The fracture mechanism changed from ductile fracture to a combination of both ductile and brittle fracture mechanism with the increase of whisker content.
TL;DR: In this article, a novel composite of 12mol% CeO2-stablized tetragonal ZrO2 reinforced with Al2O3 whiskers (called as Ce-TZP/Aw) has been prepared and studied.
Abstract: A novel composite of 12 mol% CeO2-stablized tetragonal ZrO2 reinforced with Al2O3 whiskers (designated as Ce-TZP/Aw) has been prepared and studied in this work. The objective of this investigation was to systematically study the influence of whisker-aspect-ratio on the densification behaviors, microstructure evolution, and mechanical properties of Ce-TZP/Aw composite. Results showed that the sintered density of composite increased and the grain growth tended to diminish with the decrease in whisker aspect radio. Both the fracture toughness and flexural strength reached maximum values of 475 ± 12 MPa and 11.4 ± 0.2 MPa m1/2, respectively at a whisker aspect ratio of about 12. It was also observed that the fracture toughness, flexural strength and tetragonal to monoclinic ZrO2 transformation of the dual-phase composite exhibited similar variation trend as a function of the whisker-aspect-ratio, which suggested that the stress-induced phase transformation should be the main toughening and strengthening mechanism in the Ce-TZP/Aw composite.
TL;DR: In this paper, nano-SiC particulates have been used as reinforcement in aluminium metal matrix with different weight% of nano SiC. The composites were fabricated using powder metallurgy process through cold isostatic compaction chamber.
TL;DR: In-situ mullite whisker reinforced aluminum chromium phosphate wave-transparent ceramics were designed and prepared as discussed by the authors, and the phase transformation, microstructure, mechanical and electrical properties were investigated, and the mechanisms of in-Situ growth and toughening were discussed.
Abstract: In-situ mullite whisker reinforced aluminum chromium phosphate wave-transparent ceramics were designed and prepared The phase transformation, microstructure, mechanical and electrical properties of the ceramics were investigated, and the mechanisms of in-situ growth and toughening were discussed Results indicated that the in-situ growth of mullite whisker significantly improved the mechanical properties of the matrix, especially the high temperature flexural strength The room temperature flexural strength, 1000 °C flexural strength and fracture toughness of the ceramics were 13560 MPa, 12171 MPa and 452 MPa m1/2 After sintering at 1500 °C, the optimum properties of e'r, tanδ and microwave transmittance at region 8–12 GHz were 80%, respectively The sinterability of ACP matrix was improved by the in-situ process of high mullization above 1450 °C Using ACP binder as the raw material can avoid the phase transformation from B-AlPO4 to T-AlPO4 The synthesized mullite whiskers played a role in toughening by whiskers fracture, crack deflection and whisker pulling out
TL;DR: In this paper, a mullite whisker toughened mullite coating was fabricated on the surface of SiC pre-coated C/C composites by molten-salt method with a later hot dipping process.
TL;DR: In this paper, a novel method for the rapid preparation of SiC nanowiskers by spark plasma (SP) assisted thermal treatment using SSW as the silicon source was reported.
Abstract: To reduce environmental pollution and waste of resources, it is very important to recycle valuable materials in silicon slurry waste (SSW). We report a novel method for the rapid preparation of SiC nanowhiskers by spark plasma (SP) assisted thermal treatment using SSW as the silicon source. In the preparation process, coir fibers were used as the carbon source and whisker growth substrate. At 1100–1300 °C, carbon-rich tadpole-like 3C–SiC whiskers with Fe catalyst caps were prepared by the vapor–liquid–solid growth mechanism. At 1400–1600 °C, carbon-rich, stick-like 3C–SiC whiskers without Fe catalyst caps with aspect ratios of about 40, and diameters of about 50 nm were prepared by the vapor–solid growth mechanism. The SiC whiskers grew along the [111] direction on the (111) plane at different temperatures. At the optimum temperature of 1500 °C, the silicon in SSW reacted completely, and SiC whiskers with good morphology were prepared. Furthermore, the photoluminescence (PL) spectra of SiC whiskers showed...
TL;DR: In this article, the effects of precipitates on the designed network structured composites were investigated by heat treatment without any deformation, and the microstructure results showed that the ordered α 2 phase with the size of 5nm-10nm is precipitated from matrix due to high content of α stabilizing elements and the slow cooling rate after sintering process.
TL;DR: In this article, an analytical model which accounts for strain generation (via thermal expansion mismatch) and multiple relaxation processes (rate-dependent plasticity and diffusion-controlled whisker growth) was developed to analyze the results of thermal cycling experiments.
TL;DR: In this paper, a mullite whisker-toughened silicate glass coating for SiC pre-coated carbon/carbon composites (SiC-C/C) was prepared by a molten salt and hot dipping method.
TL;DR: In this article, the benzoxazine-epoxy shape memory polymers with outstanding recovery stress improvement were prepared by filling with highly adamantine silicon carbide whisker at 0-20wt%.
Abstract: In this research, the benzoxazine-epoxy shape memory polymers with outstanding recovery stress improvement were prepared by filling with highly adamantine silicon carbide whisker at 0–20 wt%. The r...
TL;DR: In this article, in-situ SiC whisker enhanced SiC castable and spinel castable containing 20%wt of Cr 2 O 3 were prepared for the purpose of chrome-free and service longevity of lining materials for solid waste gasifier.
TL;DR: In this paper, CaCO3 whiskers were grafted with poly(methyl methacrylate) (PMMA) by in-situ emulsion polymerization using γ-methacryloxy propyl trimethoxyl silane (γ-MPS) as a coupling agent.
Abstract: In this study, calcium carbonate (CaCO3) whiskers were grafted with poly(methyl methacrylate) (PMMA) by in-situ emulsion polymerization using γ-methacryloxy propyl trimethoxyl silane (γ-MPS) as a coupling agent, and the properties of resultant whisker were determined using Fourier transform infrared (FTIR) spectroscopy, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The results show that PMMA has been successfully grafted onto the surface of CaCO3 whiskers and the maximum grafting degree (Gd) is 3.75%. The scanning electron microscopy (SEM) micrographs of the tensile-fractured surfaces show that modified CaCO3 whiskers have strong interfacial adhesion to the poly(vinyl chloride) (PVC) matrix. The tensile strength increases from 44.0 MPa for PVC composite with unmodified whisker to 49.5 MPa for that with grafted whisker. The dynamic mechanical analysis (DMA) and TGA results indicate that the composites reinforced by modified CaCO3 whiskers have much higher modulus, glass transition temperature, and better thermal stability than their counterparts reinforced by unmodified CaCO3 whiskers. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers