Mechanical stress relaxation in hetero-modulus, hetero-viscous complex ceramic materials

Abstract

Hetero-modulus, hetero-viscous complex materials have several advantages in accordance to mechanical and thermal properties comparing with the traditional ceramics and ceramic matrix composites. In this paper the authors examined in details the high speed collision processes between flying metallic objects and ceramics, such as α-Si 3 N 4 , β-Si 3 N 4 , Si 2 ON 2 , SiAlON, AlN and 3Al 2 O 3 2SiO 2 reinforced alumina matrix hybrid materials, as well as their rheo-mechanical structures and properties. Understanding the high speed collision process, material structures, rheological properties of such a complex hybrid material, the authors in this paper mathematically describe the mechanical shear stress and its relaxation during and after high speed collisions in α-Si 3 N 4 , β-Si 3 N 4 , Si 2 ON 2 , SiAlON, AlN and 3Al 2 O 3 2SiO 2 reinforced alumina matrix composites. The dynamic strength of the developed and examined corundum matrix complex materials was tested through collision with high density metallic flying bodies, with speed higher than 900 m/sec and described in works [27,29,42]. Analytical methods applied in this research were scanning electron microscopy, X-ray diffraction and energy dispersive spectrometry. Digital image analysis was applied to microscopy results, to enhance the results of transformation.

Advanced Hetero-Modulus and Hetero-Viscous Complex Materials

“…Examining the material structure Hasselman was the first who pointed out the excellent mechanical behavior of SiAlON ceramic composites, especially under high speed collisions and dynamic impacts. The high speed collision process and energy engorgement through fractures, heating, melting and phase transformation of traditional and hetero-modulus ceramics and CMCs were studied and described by the authors in works [18,21,25,36]. The mechanical stress relaxation after high speed collision in such complex materials also were also described by authors in [36,37].…”

“…The high speed collision process and energy engorgement through fractures, heating, melting and phase transformation of traditional and hetero-modulus ceramics and CMCs were studied and described by the authors in works [18,21,25,36]. The mechanical stress relaxation after high speed collision in such complex materials also were also described by authors in [36,37]. To develop hetero-modulus and hetero-viscous corundum reinforced ceramic matrix composites commercial Al 2 O 3 powders were used at purity of 94%, 96 % and 99.7 % and were compacted under traditional uni-axial and dynamic compacting methods [21,25].…”

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

“…Applying the geometrical data of the spherical, torus and conical heads as well as the friction coefficient measured earlier [8,9], the pressure was calculated for each extruder head. Fig.…”

Synthesis, Characterization and Rheological Properties of Alumina-Zeolite Mixtures

“…The research development in the field of ceramic industries is becoming a more popular and fast-growing field of material science [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Aluminium oxide (alumina; Al2O3) has superior thermal, mechanical, physical and chemical properties when compared with many other ceramics materials.…”