Practical Evolutions and Computer Simulation of Pores in BaTiO3 Ceramics during Sintering Process

2008 ◽  
Vol 368-372 ◽  
pp. 1585-1587 ◽  
Author(s):  
L.M. Li ◽  
Guo Li Ji ◽  
Y.P. Yang ◽  
Zhao Xian Xiong
Keyword(s):  
Computer Simulation ◽  
Free Energy ◽  
Grain Growth ◽  
Pore Shape ◽  
Sintering Process ◽  
Ceramic System ◽  
Ceramic Microstructure ◽  
Compact Body ◽  
Shape And Size ◽  
Good Agreement

Practical evolutions of pores in BaTiO3 ceramics during sintering are studied, including the preparation of practical BaTiO3 ceramics and observation of ceramic microstructure by SEM. The reduction of porosity and thus dense process results from the change of the free energy in the ceramic system, which is altered by the disappearing of the interface between solid and pore. The sintering process are monitored, including sintering neck growth, pore shape and size changing, grain growth and compact body contracting. Theoretical formulae during the sintering process are applied for the computer simulation. The experimental results of BaTiO3 ceramics are in good agreement with that of simulation.

scholarly journals Computer simulation of developing erosion profiles including interference effects

2021 ◽  
Author(s):  
Nastaran Shafiei
Keyword(s):  
Computer Simulation ◽  
Particle Size ◽  
Abrasive Particle ◽  
Substrate Material ◽  
Interference Effects ◽  
Individual Particles ◽  
Shape And Size ◽  
Good Agreement ◽  
Machined Surfaces ◽  
Erosion Profiles

A computer simulation was developed to predict the evolution of abrasive jet machined surfaces in unmasked substrates. Interference effects were included in the model by tracking individual particles and their collisions. The model was capable of investigating the effect of various parameters such as launch frequency, abrasive particle size and material and substrate material on the shape and size of the erosion profile, as a function of time. The model is also able to examine the effect of these parameters and the instantaneous shape of the profile on the particle interference patterns. The model was verified, for the case of a flat non eroding surface, against an existing computer simulation of particle interference effects. The predictions of the simulation were also tested against experimentally measured erosion profiles, with good agreement.

scholarly journals Computer simulation of developing erosion profiles including interference effects

2021 ◽  
Author(s):  
Nastaran Shafiei
Keyword(s):  
Computer Simulation ◽  
Particle Size ◽  
Abrasive Particle ◽  
Substrate Material ◽  
Interference Effects ◽  
Individual Particles ◽  
Shape And Size ◽  
Good Agreement ◽  
Machined Surfaces ◽  
Erosion Profiles

A computer simulation was developed to predict the evolution of abrasive jet machined surfaces in unmasked substrates. Interference effects were included in the model by tracking individual particles and their collisions. The model was capable of investigating the effect of various parameters such as launch frequency, abrasive particle size and material and substrate material on the shape and size of the erosion profile, as a function of time. The model is also able to examine the effect of these parameters and the instantaneous shape of the profile on the particle interference patterns. The model was verified, for the case of a flat non eroding surface, against an existing computer simulation of particle interference effects. The predictions of the simulation were also tested against experimentally measured erosion profiles, with good agreement.

Simulation and Optimization of Wedge-Shaped Ultrasonic Transducers Using Finite Element Method (FEM)

2013 ◽  
Vol 281 ◽  
pp. 112-115 ◽  
Author(s):  
Dan Jin ◽  
Zhao Hui Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Effect ◽  
Ultrasonic Transducers ◽  
Fe Model ◽  
Limited Size ◽  
Simulation And Optimization ◽  
Ultrasonic Flaw ◽  
Shape And Size ◽  
Good Agreement

Wedge-shaped transducers have been widely used in industry as probes for ultrasonic flowmeters or for ultrasonic flaw detectors. But by now, few studies have focused on the influence to the performance of the wedge-shaped transducers brought by their limited size. In this paper, the effect of the shape and size of wedge-shaped substrates on the whole transducer system is discussed and the shape and size of a transducer (0.5MHz) is optimized to eliminate the influence of the boundary effect by using a 2-D Finite Element (FE) model. Lastly, wedge-shaped transducers have been manufactured for experiment which shows a good agreement with the simulation.

A Simple Statistical Theory for Grain Growth in Materials.

1990 ◽  
Vol 209 ◽  
Author(s):  
P. Mulheran ◽  
J.H. Harding
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Statistical Theory ◽  
Stochastic Model ◽  
Grain Growth ◽  
Three Dimensional ◽  
Monte Carlo Procedure ◽  
Short Time ◽  
2D And 3D ◽  
Good Agreement

A Monte Carlo procedure has been used to study the ordering of both two and three dimensional (2d and 3d) Potts Hamiltonians, further to the work of Anderson et al. For the 3d lattice, the short time growth rate is found to be much slower than previously reported, though the simulated microstructure is in agreement with the earlier studies. We propose a new stochastic model that gives good agreement with the simulations.

The Free Energy Simulation Approach to Grain Boundary Segregation In Cu-Ni

1990 ◽  
Vol 209 ◽  
Author(s):  
H. Y. Wang ◽  
R. Najafabadi ◽  
D. J. Srolovitz ◽  
R. Lesar
Keyword(s):  
Monte Carlo ◽  
Free Energy ◽  
Grain Boundary ◽  
Chemical Potential ◽  
Boundary Segregation ◽  
Configurational Entropy ◽  
Accurate Method ◽  
Increasing Temperature ◽  
Atomic Coordinates ◽  
Good Agreement

ABSTRACTA new, accurate method for determining equilibrium segregation to defects in solids is employed to examine the segregation of Cu to grain boundaries in Cu-Ni alloys. The results are in very good agreement with the ones given by Monte Carlo. This method is based upon a point approximation for the configurational entropy, an Einstein model for vibrational contributions to the free energy. To achieve the equilibrium state of a defect in an alloy the free energy is minimized with respect to atomic coordinates and composition of each site at constant chemical potential. One of the main advantages this new method enjoys over other methods such as Monte Carlo, is the efficiency with which the atomic structure of a defect, segregation and thermodynamic properties can be determined. The grain boundary free energy can either increase or decrease with increasing temperature due to the competition between energetic and configurational entropy terms. In general, the grain boundary free energy increases with temperature when the segregation is strongest.

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