Development and improvemnt in laser direct joining of metal and plastic

Abstract

Metals and plastics have been used in several industrial applications such as automobiles, electronic devices and aircrafts. The joining of their dissimilar materials is important in the fundamental fields of manufacturing. Therefore, we have developed a new Laser-Assisted Metal and Plastic (LAMP) direct joining method with YAG or diode laser, which has many advantages over the conventional bonding methods with adhesives or the mechanical fastening with bolts and nuts. It was found that the LAMP joining method could produce strong joints between various metals and plastics. For example, Type 304 stainless steel and amorphous polyamide (PA) or polyethylene terephthalate (PET) plastic joint samples of 30 mm width possessed tensile shear loads of more than 3,000 N, where the fracture occurred in the base plastic sheets. Tensile shear loads and heat-cycle resistant properties of LAMP joints between SUS 304 and crystalline polyamide (PA) with fibers were also investigated and improved. The LAMP joining was characterized by the formation of small bubbles in the plastic on the metal surface. The mechanism of LAMP joining was interpreted by observing the bonding parts by SEM (Scanning Electron Microscopy) or TEM (Transmission Electron Microscopy), and by analyzing the bonding interface and the gas components inside the bubbles by XPS (X-ray Photoelectron Spectroscopy) and the special method using drilling and Q-mass method, respectively.Metals and plastics have been used in several industrial applications such as automobiles, electronic devices and aircrafts. The joining of their dissimilar materials is important in the fundamental fields of manufacturing. Therefore, we have developed a new Laser-Assisted Metal and Plastic (LAMP) direct joining method with YAG or diode laser, which has many advantages over the conventional bonding methods with adhesives or the mechanical fastening with bolts and nuts. It was found that the LAMP joining method could produce strong joints between various metals and plastics. For example, Type 304 stainless steel and amorphous polyamide (PA) or polyethylene terephthalate (PET) plastic joint samples of 30 mm width possessed tensile shear loads of more than 3,000 N, where the fracture occurred in the base plastic sheets. Tensile shear loads and heat-cycle resistant properties of LAMP joints between SUS 304 and crystalline polyamide (PA) with fibers were also investigated and improved. The LAMP joining was cha...