Advanced Hetero-Modulus and Hetero-Viscous Complex Materials

Abstract

To obtain advance hetero-modulus and hetero-viscous complex materials with extreme high dynamic strength, wear and thermal shock resistances a novel approach was applied by the authors. The developed new hetero-modulus and hetero-viscous composites were reinforced with nanoparticles and submicron fibers and whiskers of Si2ON2, SiAlON, AlN, Si3N4as well as with special additives, which had turned into amorphous phases during sintering. These types of materials have several Youngs modulus and viscosities simultaneously and have high damage tolerance and ability to absorb and dissipate the elastic energy during crack propagation. Understanding the energy engorgement of high speed collision processes, the material structures and rheological properties of such a complex hetero-modulus and hetero-viscous material the authors could mathematically describe the mechanical shear stresses in these complex materials. Analytical methods applied in this research were scanning electron microscopy (SEM), X-ray diffraction, and energy dispersive spectrometry, digital image analysis was applied to microscopy results, to enhance the results of transformations.

The influence of porosity on the elasticity and strength of alumina and zirconia ceramics

“…Young's modulus, shear modulus and Poisson's ratio are essential parameters in the study of advanced material mechanics [1][2][3]. In addition, the macroscopic behavior of ceramics can vary from brittle to quasi-plastic depending on the pore space volume [4,5].…”

Effects of Extruder Head’s Geometry on the Properties of Extruded Ceramic Products

“…Several methods exist for calculating the pressure in the heads taking the rheological and tribological behaviours of materials into account as boundary conditions [1,2,3,4]. The method in [7] was applied to calculate the theoretical magnitude of the pressure. First it uses the forces that act on an element of the total volume and sets up a differential equation (Eq.…”

“…With regard to freezing resistance, water adsorption is the decisive factor [7], which is connected to porosity. Determination of water adsorption was conducted according to the relevant standard.…”

Influence of Sintering Time on Properties of Alumina-Based Ceramic Composite

“…In spite of the fact that Na 2 O (<0,1%) and Fe 2 O 3 (<0,1%) have lower melting temperature, the most of phase transformations have occurred in solid-phase stage during sintering of this kind of ceramic composites at 1600°C. The properties of alumina-based hetero-modulus material systems [4][5][6] created at this temperature depend on the occurrences of the heat treatment times [7][8][9][10]. Therefore, the aim of this research work is the examination of microstructure, shrinkage, density, surface hardness, bending strength of alumina based hetero-modulus ceramic composites depending on the occurrences of sintering times at 1600°C.…”