Durability of Basalt Fiber Fabric Under Simulated Lunar Extreme Thermal and UV Conditions: A Comparative Study with Natural Basalt Rock

The extreme temperature cycling (−196 °C to 125 °C) and intense ultraviolet radiation on the lunar surface pose significant degradation risks to polymeric materials and their fibrous reinforcements. This work presents a comparative durability assessment between basalt fiber fabric and basalt rock powder after accelerated cyclic thermal shock treatments and UV exposure, aiming to establish a fundamental durability database for basalt fibers as candidate reinforcements for future polymer-matrix composites in lunar exploration. Multiscale characterizations reveal that regardless of the number of treatment cycles, the fiber surface morphology remains intact without cracking or etching. X-ray diffraction and Fourier-transform infrared spectroscopy confirm that the amorphous silicate network of the basalt fibers is well preserved, with no thermally induced recrystallization or compositional alteration. Thermogravimetric analysis further demonstrates that the treated fabrics retain the inherent thermal stability of pristine basalt, indirectly evidencing structural integrity. Importantly, the tensile strength of basalt yarns does not exhibit a cycle-dependent degradation trend, and the K/S colorimetric values remain stable even under combined thermal and UV exposure. Collectively, these findings confirm that basalt fiber fabric possesses exceptional resistance to lunar-mimetic aggressive environments, and its durability is comparable to that of natural basalt rock.