Multichannel measuring unit for phase interface based on C/V convertor CAV444

2015 ◽  
Author(s):  
G.S. Ji ◽  
Z.P. Chen
Keyword(s):  
Phase Interface ◽  
Multichannel Measuring ◽  
Measuring Unit

Modifiers for Rigid Polyvinylchloride Compositions of Building Purpose

2020 ◽  
Vol 787 (12) ◽  
pp. 34-39
Author(s):  
L.A. Abdrakhmanova ◽  
◽  
K.R. Khuziakhmetova ◽  
R.K. Nizamov ◽  
V.G. Khozin ◽  
...  
Keyword(s):  
Phase Interface ◽  
Thermomechanical Analysis ◽  
Favorable Effect ◽  
Heterogeneous Structure ◽  
Electron Microscopic ◽  
Wear And Tear ◽  
Thermomechanical Testing ◽  
Building Purpose ◽  
Microscopy Data ◽  
Butadiene Styrene

A comparison of small doses (up to 0.7 mass part) of impact strength modifiers of foreign and domestic production in polyvinylchloride-based compositions is given. Domestic acrylicnitrile- butadiene styrene modifiers (ABS) were used. The developed shock-resistant polyvinylchloride compositions in the presence of ABS elastifier have high melt fluidity, which has a beneficial effect on the recyclability. Changes in supramolecular structure were estimated from thermomechanical testing and electron microscopy data for both unfilled and filled PVC samples. Thermomechanical analysis showed that the presence of ABS modifier had a favorable effect on the technological properties of PVC-based samples. Electron-microscopic images indicate that in unfilled PVC samples, the heterogeneous PVC structure is expressed in the presence of ABS copolymer in comparison with foreign acrylic modifiers. When the compositions are filled with micro-heterogeneous structure in dispersion medium, the filler-polymer is formed by chalk particles, while ABS elasticifier is at the phase interface. Due to the peculiarities of the structure ABS has a higher degree of “fixation” on the surface of the chalk particles in comparison with the basic compositions containing acrylic modifiers, which with increasing chalk concentration leads to lower wear and tear on the top of the forming equipment.

scholarly journals Correlation between Microstructure and Hydrogen Degradation of 690 MPa Grade Marine Engineering Steel

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 851
Author(s):  
Heng Ma ◽  
Huiyun Tian ◽  
Juncheng Xin ◽  
Zhongyu Cui
Keyword(s):  
Crack Propagation ◽  
Base Metal ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Steel Substrate ◽  
Phase Interface ◽  
Grain Structure ◽  
Hydrogen Degradation ◽  
Two Phase ◽  
Annealed Steel

Electrochemical H charging, hydrogen permeation, and hydrogen-induced cracking (HIC) behavior of 690 MPa grade steel substrate and different heat-treatment states (annealed, quenched, normalized, tempered) are investigated by cyclic voltammetry (CV), hydrogen permeation, electrochemical H charging, and slow strain rate tensile test (SSRT). The results show that hydrogen diffuses through the steel with the highest rate in base metal and the lowest rate in annealed steel. The hydrogen-induced cracks in base metal show obvious step shape with tiny cracks near the main crack. The cracks of annealed steel are mainly distributed along pearlite. The crack propagation of quenched steel is mainly transgranular, while the hydrogen-induced crack propagation of tempered steel is along the prior austenite grain boundary. HIC sensitivity of base metal is the lowest due to its fine homogeneous grain structure, small hydrogen diffusion coefficient, and small hydrogen diffusion rate. There are many hydrogen traps in annealed steel, such as the two-phase interface which provides accommodation sites for H atoms and increases the HIC susceptibility.

scholarly journals Effect of the Characteristic Size and Content of Graphene on the Crack Propagation Path of Alumina/Graphene Composite Ceramics

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 611
Author(s):  
Benshuai Chen ◽  
Guangchun Xiao ◽  
Mingdong Yi ◽  
Jingjie Zhang ◽  
Tingting Zhou ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Volume Content ◽  
Phase Interface ◽  
Average Energy ◽  
Characteristic Size ◽  
Composite Ceramics ◽  
Graphene Composite

In this paper, the Voronoimosaic model and the cohesive element method were used to simulate crack propagation in the microstructure of alumina/graphene composite ceramic tool materials. The effects of graphene characteristic size and volume content on the crack propagation behavior of microstructure model of alumina/graphene composite ceramics under different interfacial bonding strength were studied. When the phase interface is weak, the average energy release rate is the highest as the short diameter of graphene is 10–50 nm and the long diameter is 1600–2000 nm. When the phase interface is strong, the average energy release rate is the highest as the short diameter of graphene is 50–100 nm and the long diameter is 800–1200 nm. When the volume content of graphene is 0.50 vol.%, the average energy release rate reaches the maximum. When the velocity load is 0.005 m s−1, the simulation result is convergent. It is proven that the simulation results are in good agreement with the experimental phenomena.

scholarly journals A Low Mach Number IMEX Flux Splitting for the Level Set Ghost Fluid Method

2021 ◽  
Author(s):  
Jonas Zeifang ◽  
Andrea Beck
Keyword(s):  
Level Set ◽  
Phase Interface ◽  
Time Discretization ◽  
Spectral Element ◽  
Computational Time ◽  
Minor Role ◽  
Ghost Fluid Method ◽  
Specific Level ◽  
Flux Splitting ◽  
Mach Numbers

AbstractConsidering droplet phenomena at low Mach numbers, large differences in the magnitude of the occurring characteristic waves are presented. As acoustic phenomena often play a minor role in such applications, classical explicit schemes which resolve these waves suffer from a very restrictive timestep restriction. In this work, a novel scheme based on a specific level set ghost fluid method and an implicit-explicit (IMEX) flux splitting is proposed to overcome this timestep restriction. A fully implicit narrow band around the sharp phase interface is combined with a splitting of the convective and acoustic phenomena away from the interface. In this part of the domain, the IMEX Runge-Kutta time discretization and the high order discontinuous Galerkin spectral element method are applied to achieve high accuracies in the bulk phases. It is shown that for low Mach numbers a significant gain in computational time can be achieved compared to a fully explicit method. Applications to typical droplet dynamic phenomena validate the proposed method and illustrate its capabilities.

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