Does Aristotle establish a clear link between substance and essence?

Does Aristotle establish a clear link between substance and essence?
Aristotle was born in Stageira in north Greece in 384 BC. He firstly trained in medicine, and then in 367 went to Athens to study philosophy with Plato. Aristotle opposed some of Plato's teachings.
In 338, Aristotle became tutor of Alexander the Great; after Alexander conquered Athens, Aristotle returned to Athens and set up a school of his own, Lyceum. When Alexander's died, Athens rebelled against Macedonian rule, and Aristotle risked being killed because of his political situation. To avoid being put to death, he fled…