EFFECT OF MODIFICATION WITH PARTICULATE Ti–Al–TiC POWDER REINFORCEMENTS ON THE MECHANICAL PROPERTIES OF EPOXY POLYMER COMPOSITES

Abstract

The effect of particulate powder reinforcement produced from an 85 wt.% Ti + 15 wt.% Al powder mixture processed by high-voltage electric discharges (HVED) in kerosene on the basic mechanical properties of a polymer composite based on the ED-20 epoxy oligomer. Following HVED processing, the synthesized powder had the following phase composition: 74 wt.% Ti, 15 wt.% Al, and 11 wt.% TiC with an average particle size of 10–12 μm. The reinforcement content of the composite varied from 0.25 to 2.0 wt.%. The optimal reinforcement content that significantly increased the strength and impact toughness of the composite (by 1.7–1.8 times compared to the starting matrix) was 0.5 wt.%. When the particulate reinforcement content of the composite was increased to 1.25–2.0%, the disruptive stresses reduced substantially, practically to the level of strength possessed by the starting epoxy matrix. A model was proposed to explain the extremum on dependences of the mechanical properties on the reinforcement content of the composite. The model was based on the hypothesis that the mechanical and structural factors independently influenced the composite properties. The mechanical effect was determined by the redistribution of strain-induced stresses between the matrix and reinforcement and by the adhesion between the composite components, while the structural effect was due to changes in properties of the polymer matrix in surface interaction with the reinforcement particles..