In this work, we studied the strength parameters, fractographic patterns, and the microstructure of epoxy polymer samples cured both by thermal and microwave methods at various temperature, power, and time conditions. The dependence of strength on curing conditions is determined using the tensile test method. To achieve maximum strength for both curing methods optimum conditions were found. A comparative fractographic analysis of microwave and thermal cured samples fractures having similar strength characteristics was carried out by electron microscopy. It was found that microwave field curing leads to the globules size increase in the cured epoxy polymer and an increase in the number of nanopores in the material. Plastic samples local deformation is also more pronounced during fracture, which leads to a greater difference of the main and secondary cracks propagation velocities ratio. The relationship between the studied samples optical density in the wavelength range from 360 to 2500 nm and the parameters of both curing methods (microwave and thermal) was established.
Fractal Cracks Propagation in Aluminum