Inorganic polymer materials (Geopolymers) are synthesized using alumino-silicate sources as solid components with an alkaline solution. This material is used as an alternative for building materials and provides thermal protection as foaming materials. This paper presents the preparation of these materials by the reaction between glass waste (from brown color bottles BP) with sodium hydroxide NaOH and sodium aluminum (AN5) solutions as alkali activators. For the preparation of mortars (BP-N5 and BP-AN5), sand was used as aggregate. The compressive strengths were assessed (24 and 6 MPa) respectively before heat treatment, the hydrolytic stability (PH and conductivity) tests were performed. Furthermore, hardened mortars have been heated at very high temperatures in the range of 200℃ to 800℃ within two hours. Based on the nature of the foaming behavior of such materials, various variables have changed; (80-140) % volume increase and porosity rise through the process of heat treatment, particularly at 600℃ and 800℃. On the other hand, (3.5-7) % mass reduction occurred. It can be said that the more significant porosity with different geometrical configurations (sizes and shapes) of such materials can be considered as acoustic insulation and thermal materials.
In various fields, Polymer-based composites are used extensively instead of traditional materials. The hand lay-up technology has been employed to prepare the composites of Silicon carbide particles-epoxy. Mechanical properties; shore D hardness, Flexural strength, tensile strength and impact strength were measured for all specimens. The present work has also studied the impact of different weight percentages (including 3, 6, 9, 12, 15 and 18) wt.% of SiC solid powder on the mechanical properties of fabricated samples with two average particle sizes of 75 and 105 µm. SiC particles were utilized as reinforcement with the epoxy with hardener according to the mixing of (3:1) ratio. The experimental results found that hardness, flexural strength and impact strength can be increased by increasing the weight percentage of Silicon carbide, while tensile strength is decreased with an increased weight fraction of silicon carbide. At the same time, these properties were enhanced when the particles of SiC have 75 µm more than at 105 µm.
Epoxy composite hold fabricated products used in different applications such as housing, electrical equipment, automobiles and insulators due to low thermal and electrical conductivity. The effect of metal particles (Al, Ni, Fe) content on physical and mechanical properties of such fabricated samples are investigated. Different weight fraction of metal particles (3, 6, 9, 12, and 15) wt. % with 10 wt. % SiC powder is blended by simple hand lay-up technique. According to the results of experiments, we discovered the increasing in the filler content leads to increase of the hardness and modulus elasticity are increasing too. At the same time, when filler in epoxy matrix increases, electric conductivity will increase and dielectric conductivity will decrease.
The paper presents some theoretical aspects regarding the upward velocity of particles in the cast aluminum - graphite composites. Many types of particles are used to analyze the influence of shape factor on upward velocity in aluminum melts. The calculations were made by using modified Stokes’ equation for different Reynolds number attached to graphite particles. At temperature 700-900°C the upward velocity increases about 8.5%. The viscosity of multiphase fluids depends on many factors such as: the properties of aluminum melt and complementary material; temperature of the metallic bath; concentration, shape, fineness of graphite particles and degree of agglomeration of the dispersed phase.
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