Laser alloying is possible as a one-step and a two-step procedure similar to the laser beam cladding. The BIAS uses the one-step procedure that has time advantages because of the absence of the process step of spreading the alloying material and a bonding phase. The laser beam melts the surface of the component locally with a depth of up to >1 mm. The aim of the laser beam cladding is a low dilution between the base material and the cladding material. The laser alloying intends in contrast to the laser beam cladding a liquidation of the additional material and even its distribution in the rim zone by convection during the melting. The process parameters such as intensity of the laser beam, feed rate, powder feed rate and trace offset have to be optimised so that an even depth of the alloyed layer, a low surface roughness and an even distributed alloy element is guaranteed. The laser alloying generates mostly high quality edge zones on convenient substrates. Because of the increased stability against the service conditions achieved by the laser alloying, an increased application of non-alloyed steels, cast iron or even aluminium alloys as construction material is possible. Aluminium alloys with a low density and good corrosion resistance at the atmosphere have the disadvantage of a low abrasion resistance and low melting temperatures. Consequently, especially aluminium alloys are predestined for a laser beam treatment of the rim zone with a precise local heat input. The BIAS promotes the process development and the process stabilisation of the laser alloying of aluminium alloys because of those achievements.

Figure 1: Laser alloyed surface of an aluminium alloy with silicon particles