Synthesis of ZrO۲ nanoparticle by combination of sol-gel auto-combustion method- irradiation technique, and preparation of Al-ZrO۲ metal matrix composites

Nanocrystalline ZrO۲ with particle size of about ۳۸ nm was directly synthesized by sol-gel auto-combustion method. The overall process involved three steps: formation of homogeneous sol at ۵۰-۵۵°C; formation of dried gel at ۱۱۰°C, and combustion of the dried gel at ۴۰۰°C. Experiments revealed that ZrO۲ dried gel derived from glycine (Fuel) and nitrate sol exhibited self propagating combustion at ۴۰۰°C  that  it was ignited in air. The auto-combustion was considered as a heat-induced exothermic oxidation-reduction reaction between nitrate ions and carboxyl group. After auto-combustion, products were calcined at ۶۵۰°C. ZrO۲ nano particle were incorporated into the A۳۵۶ aluminum alloy by a mechanical stirred at ۸۵۰°C and after that, cylindrical specimens were cast. After preparing the samples, mechanical properties were measured. The results of microstructure, compression and hardness tests indicated that addition of ZrO۲ nano particulates to aluminum matrix composites improved the mechanical properties. Also, Based on experiments, it was revealed that the presence of ZrO۲ reinforcement    led to significant improvement in hardness and compressive strength.

کلیدواژه ها:

ZrO۲ ، nanostructure ، mechanical properties ، Sol-gel ، Auto-Combustion ، Ultrasonic