Review on Powder Metallurgy: a Novel Technique for Recycling and Foaming of Aluminium-Based Materials

The demand for aluminum is very high worldwide because of its high strength, low density, and high electrical and thermal conductivity. Aluminum and its alloys are widely used in automotive, aerospace, packaging, kitchen utensils, construction, electrical cabling, etc. To satisfy the high demand, high production of aluminum and its alloys is essential. However, the sources of primary aluminum (aluminum extracted from ores) are limited. Hence, the efficient recycling of aluminum is vital. Conventional casting is often used to recycle aluminum and its alloys, although the efficiency of such a method is very low. The researchers are therefore working to develop highly efficient aluminum recycling techniques. Powder metallurgy is one of the novel techniques for recycling aluminum due to its high use of materials, its low energy consumption, and its quasi-final production of forms. The powder metallurgy technique is also beneficial in the manufacture of aluminum-based metal foams. There are various ways to prepare aluminum-based metal foams using the powder metallurgy technique. Aluminum-based metal foams are utilized in crashworthiness applications because of their remarkable properties, like low density and high energy absorption capacity. In this work, a study on various methods of recycling and foaming of aluminum-based materials by powder metallurgy is performed. The parameters of the powder metallurgy process, such as the compaction pressure, the weight or density of the reinforcements, and the type of reinforcement, strongly influence the recycling and foaming of aluminum. In this work, the effect of compaction pressure, weight or density fraction of reinforcements, and type of reinforcing agent on the recycling and foaming of aluminum and its alloys was investigated.