What are the uses of aluminum oxide?

Aluminum oxide, also known as alumina, has a wide range of applications due to its hardness and other properties. It is used as an abrasive in products like sandpaper and grinding wheels. In the electronics industry, it serves as a substrate for semiconductor devices. It's also a key component in the production of aluminum metal through the Hall-H茅roult process. In the medical field, aluminum oxide is used in dental materials and as an antiperspirant. Additionally, it's found in cosmetics, ceramics, and as a catalyst in various chemical processes.