If you incorrectly send Bitcoin Cash (BCH) to a SegWit (BTC) address, your funds will not be recoverable. The changes introduced by SegWit are incompatible with Bitcoin Cash, and it is impossible to access any Bitcoin Cash which has been lost in this way.
What is Segregated Witness (SegWit)?
Segregated Witness--more commonly known as SegWit--is an upgrade to Bitcoin that makes transactions more secure and efficient. By separating (segregating) the main part of the transaction data from the part which authorizes the transaction (witness), the entire transaction becomes more secure. Separating the two parts also makes the transaction data smaller, and thus allows more transactions to be sent at once.
Digital assets sent to the wrong currency address will result in permanent loss of those assets.