Product Code: ICAL08_P154

Real-time Spectrographic Analysis of the Melt Pool During Direct Laser Deposition Process
Authors:
Konrad Bartkowiak, Fraunhofer IWS; Dresden Germany
Steffen Mueller, Fraunhofer Usa; Plymouth MI USA
Presented at ICALEO 2008

Direct Laser Deposition (DLD) method is relatively new technology which has significantly matured in last few years. Although this technique has been well know from the mid 80s, process control is still under investigation. The major application of DLD is in the repair or modification of existing parts or the manufacture of completely new 2-D or 3-D parts. This technology is also commonly used for the addition of special surface layer qualities on a base material, e.g. hard surface wear resistance like W-C or diamond cladding layers. These special wear resistance layers can be applied on the top of drill bits or used as a guard layer for working machines and various automotive parts, e.g. excavator bucket tips. The real-time spectrographic analysis of the melt poll composition is one from the main factors to be improved. So far compositional monitoring in-situ is not in practical use and still requires development. It was noticed that low plasma formation occurred in direct laser deposition (DLD) and this can give significant information about the composition created in the melt pool. It is also an indication of the range of temperatures involved in the process. The work reported here centres on studies performed with various laser cladding nozzle configurations so as to investigate the feasibility of applying real-time spectroscopy and fast digital imaging to the DLD process. Also several metal compositions have already been analyzed in-situ. This research was carried out with conventional Nd:YAG, solid state, CW laser systems.