Compressive strength and thermal properties of spark plasma sintered Al-Al₂O₃ nanocomposite

In this work, compressive and thermal properties of aluminum, milled aluminum, and Al-10Al₂O₃ composite processed via ball milling (BM) and spark plasma sintering (SPS) were investigated. The microstructural features of powders and sintered samples were characterized using optical and scanning electron microscopy. A universal testing machine was used to determine the compressive properties of the consolidated samples. The thermal conductivity and coefficient of thermal expansion of the developed materials were characterized using a hot disc thermal constant analyzer and a dilatometer, respectively. The Al-10Al₂O₃ composite possessed hardness of 1309.7 MPa, yield strength of 311.4 MPa, and compressive strength of 432.87 MPa compared to hardness of 326.3 MPa, yield strength of 74.33 MPa, and compressive strength of 204.43 MPa for aluminum. The Al-10Al₂O₃ composite had thermal conductivity value 81.42 W/mK compared to value of 198.09 W/mK for aluminum. In the temperature range from 373 K to 723 K, the composite had lower CTEs ranging from 10 × 10⁻⁶ to 22 × 10⁻⁶/K compared to 20 × 10⁻⁶ to 30 × 10⁻⁶/K for aluminum.