Mechanical properties of cured epoxy resin

We study experimentally the influence of mass fraction of L-20 hardener cold cure on mechanical properties of epoxy diane resin ED-20. We measure the hardness, tensile strength, bending strength and impact strength of resin at different values of the hardener mass fraction. It is found that the ratio hardener mass fraction of 1:0.9 leads to the highest values of the hardness, tensile strength, compressive strength and bending strength. The impact viscosity is maximum at the ratio hardener mass fraction of 1:0.8. The optimal ratio of a non-toxic safe hardener to the resin is derived based on obtained mechanical characteristics.

Study of the Impact Viscosity of the Epoxy Composite Modified Technical Carbon

This article discusses effect of filler concentration on impact strength of an epoxy resin composite. The optimal ratio of resin and hardener is defined. Research of the effect of the concentration of the filler - carbon black P505 on the impact strength of a composite material based on epoxy resin ED-20 is made. According to the results of the study, it is shown that with an increase of concentration of the filler from P505 carbon black, the toughness decreases. Fractographic studies of the fracture surfaces of composites were also carried out, which indicate that the introduction of a filler leads to a decrease in the surface energy of destruction. Thus, studies of epoxy composite modified with technical carbon grade P505 showed a decrease in impact strength up to 4 times, depending on the increase in the mass fraction of the filler.

Destruction of Epoxy-Based Composite Materials under the Influence of Impact Load

Some features of impact destruction are shown on the example of a composite material with epoxy matrix and hybrid filler, magnetic particles of iron oxide of micron size and nanoparticles of iron oxide are used in the capacity of it. Dependence of the impact viscosity of the material on the temperature was discovered experimentally, which demonstrates the increase of this value at the decrease of the temperature.

INVESTIGATION INTO PHYSICAL AND MECHANICAL PROPERTIES OF POLYMERIC SAND USED FOR COWSHED FLOORING

Physical and mechanical properties of the polymeric sand used as floor covering in cattle stalls were investigated. Samples of the polymeric sand were tested under static and dynamic stress, an impact test was done, mechanical characteristics were measured, and the material structural efficiency was evaluated. The polymeric sand tile appeared strong, reliable and durable material. The study material exhibited viscoelasticity. The polymeric sand samples demonstrated impact viscosity in the range 242,3– 548,3 kJ/m2 . The figure was 3,5–13,7 times higher than that of gray cast iron and was comparable with some classes of carbon structural steel. Mechanical properties of the polymeric sand were analysed. The characteristics revealed in the analysis can be used in dimensioning and designing products made from polymeric sand under various strength indices.

Influence of filler on the properties of compositions based on epoxy oligomer

The properties of composites based on epoxy oligomer (EDO) and woody ash (WA) have been explored. As a result of the studies, it was proved that WA addition doubles the impact viscosity of composition, increases the density up to 40%, the hardness of the composite gradually increases with an increase of WA content. A uniform distribution of WA particles in the matrix is obtained.

Carbon additives influence on mechanical properties of titanium near-alpha alloy

The article considers the influence of carbon in the range from 0.008 to 0.18 mass. % at the temperature of complete polymorphic transformation, microstructure and mechanical properties of near-alphatitanium alloy systems Ti–6.2Al–Sn–Zr–(2.19–3.53) Moeq–(0.18–0.28)Si–(0.008–0.18)С. Alloying with carbon is possible due to special titanium sponge or industrial ligatures. Six experimental forgings performed on bimodal microstructured ingots allowed to establish a rational level of carbon. It is shown that carbon alloying at solubility limit (up to 0.08% by weight) increases the heat resistance of the material, while a similar alloying with silicon gives a greater effect. The carbon effect on the strength at room temperature is negligible. Negative effect of carbon on the impact toughness of the alloys is marked. For the selected carbon alloying level at strength of 1165–1180 MPa, the impact viscosity remains at an acceptable level of KCU = 330–381 kJ/m2 . The alloys of the investigated system allow hot deformation in heavy conditions under hammer forging at relatively low temperatures of the two-phase region.