Laser ND: YAG Welding of Glass Fiber Polypropylene, Polyamide and Polyester Composite to Thermoplastic Polyamide
Polymer matrix composites are currently used in a wide range of activity sectors, ranging from consumer electronics to the aeronautics and space industries. The excellent mechanical properties and low specific weight form the basis of the increasing volume of structural applications. The joining of two components in composite material is usually done through bonded, screwed or riveted connections. The first case, which is the most usual one, has a major limitation, that is the glues need a certain curing time, so it is not possible to send the worked set to the next stage of the manufacturing process immediately after gluing. But the screws and rivets have another problem. In fact, they require the machining of holes in the parts to be connected, which introduces defects and concentration of stresses that can cause the structure to fail. Laser welding of composites has two major advantages: it is extremely fast; and it is very accurate and easy to automate. However, only recently the laser welding of composites has been tested. This work analyzes the laser weldability of glass fiber polypropylene, polyamide and thermoplastic polyester composite to thermoplastic polyamide. Single lap joint was laser welded and was used the shear test to find the feasibility of the joint. The results are promising. In fact, some welded joints present a mechanical shear strength of 20 MPa, which value is similar to one bonded joint.
Index Terms - Laser welding of composites, welding of glass fiber polyamide, welding of thermoplastic polyamide, weld ability of composites.