Zhi Wang¹, Jinming Cao¹, Zhonglei Liu¹, Yuhong Zhao^1,2,3,*

CMC-Computers, Materials & Continua, Vol.81, No.1, pp. 213-228, 2024, DOI:10.32604/cmc.2024.055169 - 15 October 2024

Abstract Recent years, the polarization response of ferroelectrics has been entirely studied. However, it is found that the polarization may disappear gradually with the continually applied of electric field. In this paper, taking K_0.48Na_0.52NbO₃(KNN) as an example, it was demonstrated that the residual polarization began to decrease when the electric field frequency increased to a certain extent using a phase-field methods. The results showed that the content of out-of-plane domains increased first and then decreased with the increase of applied electric field frequency, the maximum polarization disappeared at high frequencies, and the hysteresis loop became elliptical. In More >

Pan Chen^1,2,3, Baojin Chu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09199

Abstract Generally, film dielectric materials often exhibit size-dependent structure and electric properties. In this work, we demonstrate a similar behavior in bulk Na_0.5Bi_0.5TiO₃ (NBT)-based polycrystalline ceramics. According to the results from X-ray diffraction, the (Na_0.5Bi_0.5)_0.92Ba_0.08Ti_0.99Mg_0.01O_2.99 (NBT8M1.0) ceramic showed a complex structure that consists of rhombohedral, tetragonal and cubic symmetries. We found, when decreasing the thickness of a ϕ 10 mm NBT8M1.0 ceramic from 1230 μm to 230 μm, the ceramic showed increased content of cubic symmetry (CC) from 28% to 56%. Meanwhile, the piezoelectric response (d₃₃₎ increased from 107 pC/N to 134 pC/N and the depolarization temperature (T_d) decreased… More >

Yuanzhe Li¹, Qiwen Liu^2,*, Lisheng Liu², Hai Mei²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09500

Abstract The ablation of ultra-high-temperature ceramics (UTHCs) is a complex physicochemical process including mechanical behavior, temperature effect, and chemical reactions. In order to realize the structural optimization and functional design of ultra-high temperature ceramics, a coupled thermo-chemomechanical bond-based peridynamics (PD) model is proposed based on the ZrB₂ ceramics oxidation kinetics model and coupled thermomechanical bond-based peridynamics. Compared with the traditional coupled thermo-mechanical model, the proposed model considers the influence of chemical reaction process on the ablation resistance of ceramic materials. In order to verify the reliability of the proposed model, the thermomechanical coupling model, damage model and… More >

Liang Yu^1,2,3, Yuan Liu^1,2,3, Xiuling Cao^4,*, Yulong Yan^1,2,3, Chen Zhang^1,2,3, Yanli Jiang^1,2,3,*

Journal of Renewable Materials, Vol.11, No.7, pp. 3057-3072, 2023, DOI:10.32604/jrm.2023.025732 - 05 June 2023

Abstract In this study, the effect of sintering temperature and the addition of kaolin, a sintering agent, on the microscopic, phase, and mechanical properties of ceramics were investigated using secondary aluminum dross (SAD) as the main component in the manufacturing of ceramics. The basic phases of the ceramics were Al₂O₃, MgAl₂O₄, NaAl₁₁O₁₇, and SiO₂ without the addition of kaolin. The diffraction peaks of MgAl₂O₄, NaAl₁₁O₁₇, and SiO₂ kept decreasing while those of Al₂O₃ kept increasing with an increase in temperature. In addition, the increase in temperature promoted the growth of the grains. The grains were uniform in size and regular… More > Graphic Abstract

Yuanzhe Li¹, Qiwen Liu^2,*, Lisheng Liu², Hai Mei²

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 417-439, 2023, DOI:10.32604/cmes.2022.021258 - 29 September 2022

Abstract The ablation of ultra-high-temperature ceramics (UTHCs) is a complex physicochemical process including mechanical behavior, temperature effect, and chemical reactions. In order to realize the structural optimization and functional design of ultra-high temperature ceramics, a coupled thermo-chemo-mechanical bond-based peridynamics (PD) model is proposed based on the ZrB₂ ceramics oxidation kinetics model and coupled thermo-mechanical bond-based peridynamics. Compared with the traditional coupled thermo-mechanical model, the proposed model considers the influence of chemical reaction process on the ablation resistance of ceramic materials. In order to verify the reliability of the proposed model, the thermo-mechanical coupling model, damage model and… More >

P. V. Rajesh¹, Kanak Kalita^2,*, Xiao-Zhi Gao³

CMC-Computers, Materials & Continua, Vol.70, No.2, pp. 2415-2433, 2022, DOI:10.32604/cmc.2022.018247 - 27 September 2021

Abstract Bone grafting is a surgical restructuring procedure of replacing broken bones and reconstructing missing bone pieces so that complex bone fractures can be repaired to avoid any serious health risk as well as permanent bone disfiguration. Normally, human bones tend to regenerate and heal completely from fracture. But it needs a small scaffold to provide the necessary space to grow. Bone implants allow a broken bone to grow seamlessly. Traditionally, non-corrosive metal alloys are used for fixing broken bones. A metal plate is fastened between two ends of broken bones to join them. However, issues… More >

Hang Xu, Huiling Du^*, Le Kang, Qiudi Cheng, Danni Feng, Siyu Xia

Journal of Renewable Materials, Vol.9, No.12, pp. 2129-2141, 2021, DOI:10.32604/jrm.2021.016090 - 22 June 2021

Abstract The large-scale accumulation and pollution of solid mining waste is an urgent issue. Coal gangue is a prominent type of solid waste, and shows promise for use in high value-added products due to its content of many important compounds, including SiO₂ and Al₂O₃. This study proposed the preparation of highly porous ceramics from coal gangue, coal slime, and coconut palm fibers. The ceramics were produced at a sintering temperature of 950°C with a fiber content of 6 wt%, which led to the formation of porous ceramics with a porosity of 66.93%, volume density of 1.0329 g/cm3… More > Graphic Abstract

Yihua Xiao^{1, *}, Hecheng Wu¹, Xuecheng Ping^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 923-954, 2020, DOI:10.32604/cmes.2020.07686 - 01 March 2020

Abstract Ceramics are extensively used in protective structures which are often subjected to projectile impacts. During an impact process of a ceramic target by a projectile, fragmentation occurs in both the target and the projectile. It is challenging to simulate such events and predict residual mass and velocity of the projectile. In this work, we attempt to use smoothed particle hydrodynamics (SPH) in LS-DYNA to reproduce fragmentation of the target and the projectile and predict residual mass and velocity of the projectile during a projectile impact of a ceramic target. SPH models for an alumina ceramic… More >

John D. Clayton^1,2,*, R. Brian Leavy¹, Jaroslaw Knap³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.3, pp. 50-52, 2019, DOI:10.32604/icces.2019.05118

Abstract Diffuse interface models and simulations capture deformation and failure of polycrystalline ceramics with multiple phases. Two heterogeneous ceramic solids are investigated. The first consists of a boron carbide matrix phase embedded with titanium diboride grains. The second consists of diamond crystals with a smaller fraction of silicon carbide grains, where the latter may encapsulate the former in a micro- or nano-crystalline matrix and/or may be interspersed as larger micro-crystals. A general constitutive framework suitable for representing behaviors of all phases of each material system is reported. This framework is implemented in three-dimensional (3D) finite element More >

John D. Clayton^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 333-350, 2019, DOI:10.32604/cmes.2019.06342

Abstract A theory invoking concepts from differential geometry of generalized Finsler space in conjunction with diffuse interface modeling is described and implemented in finite element (FE) simulations of dual-phase polycrystalline ceramic microstructures. Order parameters accounting for fracture and other structural transformations, notably partial dislocation slip, twinning, or phase changes, are dimensionless entries of an internal state vector of generalized pseudo-Finsler space. Ceramics investigated in computations are a boron carbide-titanium diboride (B₄C-TiB₂) composite and a diamond-silicon carbide (C-SiC) composite. Deformation mechanisms-in addition to elasticity and cleavage fracture in grains of any phase-include restricted dislocation glide (TiB₂ phase), deformation… More >