Laser marking forged aluminium presents us with a few challenges in achieving high quality marking, and presents a very difficult application dealing with two contrasting forms. The product was to be used for the wheel nut on a vehicle.
The forging of aluminium alloys, is the process of converting a uniform blank shape into a final product by hammering the material between shaped or flat dies. This working process may take place in one stage or several stages. The great majority of aluminium forgings are made in the heat-treatable alloys, but forgings in pure aluminium and in some of the non-heat-treatable alloys find application in certain fields. The technology has now reached an advanced stage of development, and precision forgings are used for many highly stressed parts, such as in aircraft undercarriage gear, internal combustion engines and other power units. Forged components have an advantage of near net shape, minimising further machining.
In order to ensure a good result, the power selection has to be high, but not so high, as it damages the blackening. If the laser marking process if set too low, then the resulting surface will be a mix of bare aluminium and patches of the blackened surface treatment, and the surface being undulated. If you then try to clean the affected areas, the results are not great. Sometimes, it is better with applications like this, to use very high power settings, then go back and clean afterwards. The high power selection, will ensure a clean process throught the top tough layer of the aluminium.
We used an Nd:YAG flash lamp laser, to complete the laser marking forged aluminium. High energy levels are required, to ensure process completion through the top layer of the material, while a lower energy level was used to clean up the staining from the first pass.
The combined precision of the beam placement, along with our tooling design, means the part and mark are precisely aligned, every time we set up a new batch of parts. Tooling design uses a cross slot and dowel locating system, while jigging is specifically designed to accommodate both simple and complex shapes as required. The operating software, holds positional data, so the laser and tooling are aligned.
If you would like further information on this laser marking application, or any other application, please request a call back, or talk to one of our laser marking specialists on 01737 826902.