Akhlaghi, F., R. Eslami-Farsani, et al. Journal of Composite Materials, 2013, 47(27), 3379-3388.
This work investigated the suitability of basalt fibers as reinforcements for metal matrix composites through various thermal stability and mechanical properties experiments. The residual tensile strength values of basalt fibers after exposure to different temperatures in a furnace for predetermined times and/or immersion in molten aluminum for different times were evaluated and the processing method was optimized. It was found that although the mechanical properties of aluminum/basalt composites were much lower than expected as predicted by the law of mixtures, they were still sufficient for some engineering applications.
Optimized processing method
· Basalt fiber strength diminishes over time at elevated temperatures due to a shift from amorphous to crystalline structure. While fibers retain approximately 80% of their strength after a 5-minute exposure at 300°C, a brief contact with molten A413 aluminum alloy at 600±5°C results in a 50% strength reduction. Subsequent heating at 300°C following this alloy contact further degrades fiber strength. Consequently, maintaining aluminum-coated fibers below 300°C for no more than 7 minutes is crucial to preserve their integrity.
· Aluminum/basalt laminates, containing 16% fiber volume, were produced by immersing single-layer preforms in molten alloy for 2 seconds, followed by hot pressing to maximize density and tensile strength. Composite density increased with hot pressing pressure, temperature, and duration. However, ultimate tensile strength (UTS) did not improve above 300°C and deteriorated beyond 7 minutes. Therefore, optimal hot pressing parameters were determined to be 300°C, 7 minutes, and 630 MPa.
Lilli, M., et al. Composites Part B: Engineering, 2023, 262, 110826.