Fracture Toughness of Moldable Low-Temperature Carbonized Elastomer-Based Composites Filled with Shungite and Short Carbon Fibers

This work evaluated the fracture toughness of the low-temperature carbonized elastomer-based composites filled with shungite and short carbon fibers. The effects of the carbonization temperature and filler content on the critical stress intensity factor (K-1c) were examined. The K-1c parameter was obtained using three-point bending tests for specimens with different l/b ratio (notch depth to sample thickness) ranging from 0.2 to 0.4. Reliable detection of the initiation and propagation of cracks was achieved using an acoustic sensor was attached to the samples during the bending test. The critical stress intensity factor was found to decrease linearly with increasing carbonization temperature. As the temperature increased from 280 to 380 degrees C, the K-1c parameter was drastically reduced from about 5 to 1 MPa center dot m(1/2) and was associated with intense outgassing during the carbonization step that resulted in sample porosity. The carbon fiber addition led to some incremental toughening; however, it reduced the statistical dispersion of the K-1c values.

Automated summary

This study evaluated the fracture toughness of low-temperature carbonized elastomer-based composites filled with shungite and short carbon fibers. The results showed that the increase in carbonization temperature resulted in a decrease in the critical stress intensity factor, while the addition of carbon fibers enhanced the toughness of the material.