Methods for joining a first thermoplastic substrate with a second thermoplastic substrate

A method for joining a first multi-ply thermoplastic composite part with a second multi-ply thermoplastic composite part, the method comprising:

• co-consolidating a first semicrystalline thermoplastic film with the first multi-ply thermoplastic composite part to yield a first co-consolidated structure, the first multi-ply thermoplastic composite part comprising a first polyaryletherketone material having a first melting temperature, the first semicrystalline thermoplastic film comprising a second polyaryletherketone material having a second melting temperature, the second melting temperature being less than the first melting temperature, wherein the first semicrystalline thermoplastic film defines a first bonding surface on a first side of the first co-consolidated structure;
• co-consolidating a second semicrystalline thermoplastic film with the second multi-ply thermoplastic composite part to yield a second co-consolidated structure, the second multi-ply thermoplastic composite part comprising the first polyaryletherketone material, the second semicrystalline thermoplastic film comprising a third polyaryletherketone material having a third melting temperature, the third melting temperature being less than the first melting temperature, wherein the second semicrystalline thermoplastic film defines a second bonding surface on a second side of the second co-consolidated structure;
• positioning the first co-consolidated structure and the second co-consolidated structure such that the first bonding surface is facing the second bonding surface;
• positioning a third semicrystalline thermoplastic film between and in contact with both the first bonding surface of the first co-consolidated structure and the second bonding surface of the second co-consolidated structure, the third semicrystalline thermoplastic film comprising a fourth polyaryletherketone material having a fourth melting temperature;
• heating the first bonding surface on the first side of the first co-consolidated structure and the second bonding surface on the second side of the second co-consolidated structure;
• and
• pressing the first bonding surface on the first side of the first co-consolidated structure into engagement with the second bonding surface on the second side of the second co-consolidated structure to yield a semicrystalline film joined thermoplastic assembly.