The researchers studied how burning temperature affects the use of rice husk silica to strengthen recycled Aluminium chip AA7075. They found that burning rice husk at 700°C keeps the silica in an amorphous phase, while burning at 1000°C makes it semi-crystalline. Increasing the amount of rice husk silica in the composite material increased porosity and water absorption but also improved hardness. The best results were seen with amorphous silica burned at 700°C, showing potential for enhancing material hardness.