Application of spherical indentation and the materials knowledge system framework to establishing microstructure-yield strength linkages from carbon steel scoops excised from high-temperature exposed components

To investigate the fracture behavior of cement-bonded corundum castables, various cement contents and pre-treating temperatures have been comparatively studied using the wedge splitting method and the digital image correlation technique. The results show that the microstructure enhances the mechanical properties, so the fracture energy and the maximum load as well as the fracture modes are affected correspondingly. The castables demonstrate the highest fracture energy and maximum load at 1600 °C with cement content of 10 wt% due to an appropriate amount of CA6. At the temperatures of 110 and 1100 °C, the crack propagation within the matrix and along the interface are dominated whereas within the aggregates significantly increased at 1600 °C, leading to the brittleness of materials. However, increasing the cement content can reduce their brittleness, caused by the maximum strain in thex-direction, largest length of the main crack, and high ratio of crack propagation in the matrix.

Investigation of fracture behavior of cement-bonded corundum castables using wedge splitting test and digital image correlation method

The use of reticulated porous ceramics(RPCs) was of great interest in high-temperature catalytic application owing to their high surface area. In order to further optimize the pore structure and mechanical properties of RPCs, vacuum infiltration with CaCO3-Al2O3 slurries process was applied to fabricate Al2O3-ZrO2 RPCs with hierarchical pore structures. The pores within ceramic struts were prepared by processes of CaCO3 decomposition and calcium hexaluminate grains growth. And the compressive residual stress was formed within multi-layered struts owing to the difference in the thermal expansion of coating layer and ceramic struts, which was established as a key factor in improving the mechanical properties and thermal shock resistance of RPCs. Furthermore, the size of pores within struts ranging from 5 μm to 14 μm affected the thermal shock resistance of RPCs significantly based on grey incidence analysis. And the potential of this materials as high-temperature catalyst supports was demonstrated.

A novel design of Al2O3-ZrO2 reticulated porous ceramics with hierarchical pore structures and excellent properties

This prospective offers a new Bayesian framework that could guide the systematic application of the emerging toolsets of machine learning in the efforts to address two of the central bottlenecks encountered in materials innovation: (i) the capture of core materials knowledge in reduced-order forms that allow one to rapidly explore the vast materials design spaces, and (ii) objective guidance in the selection of experiments or simulations needed to identify the governing physics in the materials phenomena of interest. The framework builds on recent advances in the low-dimensional representation of the statistics describing the material’s hierarchical structure.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/8D6C0A4F120682A900A9341021C8B0BA/S2159685919000569a.pdf/div-class-title-a-bayesian-framework-for-materials-knowledge-systems-div.pdf

A Bayesian framework for materials knowledge systems

Fabrication and characterization of a mullite-foamed ceramic reinforced by in-situ SiC whiskers

Effects of nano-alumina content on the formation of interconnected pores in porous purging plug materials

Effects of critical particle size on properties and microstructure of porous purging materials

Fabrication of calcium hexaluminate-based porous ceramic with microsilica addition

The present invention relates to a dispersive air brick and a preparation method thereof According to the technical scheme of the invention, 50 to 80 wt% of plate-shaped corundum is adopted as an aggregate 12 to 32 wt% of aluminum oxide fine powders, 5 to 10 wt% of alumina micro powders and 3 to 8 wt% of a binding agent are adopted as matrix materials According to the method, firstly, the matrix materials are uniformly mixed, and then the matrix materials and the aggregate are put into a mixer 01 to 03 wt% of a water reducing agent and 4 to 6 wt% of water, counted relative to the sum of the aggregate and the matrix materials, are additionally added The obtained mixture is stirred for 3 to 5 minutes, and then is cast and molded After an obtained product is standing at the room temperature for 20 to 30 hours, the obtained product is dried for 22 to 26 hours at the temperature of 90 to 120 DEG C then the obtained product is thermally insulated for 3 to 6 hours at the temperature of 1450 to 1650 DEG C In this way, the dispersive air brick can be obtained The plate-shaped corundum is in the form of equal-diameter particles, and the particle sizes of the equal-diameter particles are 2 to 5 mm The method has the advantages of simple process, low labor intensity, high production efficiency, no pollution to the environment, and low cost The prepared dispersive air brick is good in air permeability, strong in impurity-removing capability, excellent in thermal shock stability and good in penetration resistance performance

Dispersive air brick and preparation method thereof

In this study, light-weight insulation materials were prepared with calcined flint clay as the main material and sawdust was infused by sols as a pore forming agent. Micro-porosity and properties of the prepared insulation materials were investigated and were found to have better comprehensive properties. Apparent porosity, bulk density and cold crushing strength of the compositions containing 40 wt% calcined flint clay, fired at 1400°C for 3 h, were found to be 71%, 0.85 g.cm–3 and 2.65 MPa, respectively. Thermal conductivity of the material was 0.133 W.m–1.K –1 at 300°C. When sawdust was soaked by 0 wt% sol, microstructure of the materials showed irregular pores. When sawdust was infused with 7 wt% alumina sol, the micropores were wrapped with larger pore. Meanwhile, the original pore was refined, and cold crushing strength and thermal conductivity were also optimized. When the sawdust was soaked in alumina sol, the cold crushing strength increased to 3.3 MPa and the thermal conductivity decreas...

Wang Qingheng

Papers

Effects of nano-alumina content on the formation of interconnected pores in porous purging plug materials

Effects of critical particle size on properties and microstructure of porous purging materials

Fabrication of calcium hexaluminate-based porous ceramic with microsilica addition

Dispersive air brick and preparation method thereof

Micro-Porosity and Properties of Light-Weight Insulation Refractories Based on Calcined Flint Clay