Automotive Welding: Industrial Lasers and their Application

The use of lasers in automotive manufacture has increased dramatically over recent years to a position where about 15 per cent of all industrial processing lasers are installed in production. While traditionally these lasers have been used in cutting applications, their use in welding is on the rise. TWI's Steve Riches reports...

IN a survey in 1992, about 20 per cent of the lasers installed in the automotive industry were used in welding applications. Since that time, there has been an explosion of growth in welding applications, particularly involving steel manufacturers, for tailored blank manufacture and in body-in-white welding applications.

Industrial Laser Types

There are two main types of industrial laser of interest to structural fabrication; CO2 and Nd:YAG lasers. High power CO2 lasers are predominantly used for the welding of automotive components, such as gears and transmission components, which require circular and annular welds and in tailored blank applications. The majority of lasers have a power of 6kW or less.

High power Nd:YAG lasers are now available at workpiece powers of 4kW, which have fibre-optic beam delivery. The welding applications are concentrated in body-in-white assembly. Higher power equipment is likely to be developed in the next 2-3 years and there are likely to be improvements in the efficiency of Nd:YAG lasers with the arrival of diode pumped Nd:YAG lasers.

Within the laser industry, one of the main advances in the past two years has been in diode lasers (wavelength 0.8-0.9µm), where 2kW systems are now commercially available. However, at the current status of development, the power densities required for welding of sheet materials used in the automotive industry (about 1x106 W/cm2) have not been achieved. Research work is underway in Germany to develop diode lasers and their applications and this situation may change in the next three years.