Effects of titanium carbide on modified magnesium oxysulfate cement: Microstructure and mechanical properties

This study explores the effects of micro and nano titanium carbide (TiC) on the properties of magnesium oxysulfate cement with dosages of 1-5%. The flexural and compressive strength of composites were 15-21 MPa and 82-95 MPa at 28d. TiC reduced brittleness by improving displacement and energy absorption capability to 82 % and 114 %. Curing age influenced flexural strength by increasing both displacement and energy absorption capability, but the compressive strength development depends primarily on energy absorption capability. The 517 phases in clusters or rings grown from interfaces with gels contributed to high strength of cement. The poor performance of composites containing 5% nano-TiC was attributed to the formation of magnesium hydroxide crystals. TiC decreased the water resistance due to the formation of long needle crystals. Carbonization did not reduce compressive strength statistically but weakened flexural strength by 18%-56 %. Evaluation based on 15 indicators concluded the optimal sample with 1 % nano-TiC, providing insights into the design of magnesium oxysulfate cement products with high performance.