Titanium diboride (TiB₂) is a ceramic material known for its high strength, durability, hardness, and wear resistance. Its applications are currently limited to specialized areas such as impact-resistant armor, cutting tools, crucibles, and wear-resistant coatings. The paper examines the physical, mechanical, and thermal properties of TiB₂ as a function of density and grain size, addressing the variability in material properties due to batch-to-batch differences in processing procedures. The study extends previous work on alumina and silicon carbide, focusing on the statistical characterization of microstructure and its correlation with property values. Key findings include: 1. **Elastic Moduli**: The elastic modulus (E) and shear modulus (G) of TiB₂ depend on density and chemical composition, with higher mass fractions of TiB₂ yielding higher moduli. The elastic modulus increases with temperature, while the shear modulus decreases. 2. **Strength**: Flexural strength (σf) decreases with increasing grain size but increases with temperature up to 1500 °C. Compressive strength (σc) is approximately linearly dependent on density and shows a significant dependence on grain size. 3. **Fracture Toughness**: Fracture toughness (KIC) has a maximum value for mean grain sizes in the range of 5 to 12 μm, influenced by both grain size and measurement methods. 4. **Hardness**: Vickers hardness (HV) is not significantly affected by density or grain size but shows a power-law dependence on indentation load. 5. **Creep**: Creep rates are described by the Norton model, with parameters evaluated from flexural creep data. 6. **Friction and Wear**: Friction and wear characteristics are influenced by temperature, sliding speed, and contact stress. The coefficient of friction has a minimum near 800 °C and varies with the ratio of sliding speed to contact stress. 7. **Specific Heat**: Specific heat (Cp) increases monotonically with temperature, fitting a linear interpolation formula. 8. **Thermal Transport**: Thermal diffusivity (D) and thermal conductivity (κ) are also temperature-dependent, fitting exponential interpolation formulas. The study concludes that while there is significant variability in property values among different batches of TiB₂, trends in property values can be determined by relating them to the statistics of the microstructure. These trends are crucial for understanding and predicting the behavior of TiB₂ in various applications.Titanium diboride (TiB₂) is a ceramic material known for its high strength, durability, hardness, and wear resistance. Its applications are currently limited to specialized areas such as impact-resistant armor, cutting tools, crucibles, and wear-resistant coatings. The paper examines the physical, mechanical, and thermal properties of TiB₂ as a function of density and grain size, addressing the variability in material properties due to batch-to-batch differences in processing procedures. The study extends previous work on alumina and silicon carbide, focusing on the statistical characterization of microstructure and its correlation with property values. Key findings include: 1. **Elastic Moduli**: The elastic modulus (E) and shear modulus (G) of TiB₂ depend on density and chemical composition, with higher mass fractions of TiB₂ yielding higher moduli. The elastic modulus increases with temperature, while the shear modulus decreases. 2. **Strength**: Flexural strength (σf) decreases with increasing grain size but increases with temperature up to 1500 °C. Compressive strength (σc) is approximately linearly dependent on density and shows a significant dependence on grain size. 3. **Fracture Toughness**: Fracture toughness (KIC) has a maximum value for mean grain sizes in the range of 5 to 12 μm, influenced by both grain size and measurement methods. 4. **Hardness**: Vickers hardness (HV) is not significantly affected by density or grain size but shows a power-law dependence on indentation load. 5. **Creep**: Creep rates are described by the Norton model, with parameters evaluated from flexural creep data. 6. **Friction and Wear**: Friction and wear characteristics are influenced by temperature, sliding speed, and contact stress. The coefficient of friction has a minimum near 800 °C and varies with the ratio of sliding speed to contact stress. 7. **Specific Heat**: Specific heat (Cp) increases monotonically with temperature, fitting a linear interpolation formula. 8. **Thermal Transport**: Thermal diffusivity (D) and thermal conductivity (κ) are also temperature-dependent, fitting exponential interpolation formulas. The study concludes that while there is significant variability in property values among different batches of TiB₂, trends in property values can be determined by relating them to the statistics of the microstructure. These trends are crucial for understanding and predicting the behavior of TiB₂ in various applications.