Laser cladding with mixed powder feed

Cladding a metallic surface by blowing powder into a melt pool generated by a laser has been shown to be possible in previous work. (1).In this paper the process is developed further in three ways to allow in situ alloying by blowing mixed powder into the laser generated melt pool. In the first method a single hopper containing a mixed powder feeds a single argon blown delivery pipe. In the second method a multiple hopper system feeds the individual alloying elements into a single argon blown delivery pipe. In the third method a multiple hopper system feeds a multiple delivery pipe arrangement.It is shown in these preliminary results with the Fe/Cr/Ni system that in situ alloying is possible though homogeneity is dependent upon the cladding speed, location within the tracks and impingement location of the powder feed. There is a speed below which macroscopically homogeneous clad layers were obtained. In the multiple delivery system layered deposits could be made if the location of the delivery tubes was carefully adjusted.