Applied spectroscopy in situ during direct laser deposition process
Abstract
The Direct Laser Deposition (DLD) method is becoming more popular and has recently been successfully applied in commercial workshops. It is mainly used for reconditioning of worn and damages parts and eliminating them from scrap. However, DLD technique shows great potential for direct manufacture, where high accuracy, low distortion and small Heat Affected Zone (HAZ) effects are required. The high accuracy required makes DLD process control a challenge, this is an on going development process continually being updated from year to year. However, compositional monitoring is one of the major players to reach full process control, but is still under investigation. The in situ application of spectroscopy seems to be right tool to get more information about the composition created during DLD. This is a very dynamic and powerful tool, by identifying the elements by spectra lines, can determine how the melt pool composition has been changed by laser irradiation in real-time. T his research will allow the development of a non-contact monitoring technique for the DLD process and produce significant data support for the modeling of a temperature control method. The work reported here concentrates on studies performed with new high-powered solid state, CW laser system (diode laser) to investigate the feasibility of applying real-time spectroscopy to the DLD process.
