Plasma Spectroscopy in Rapid Manufacturing: Copper, Titanium, Aluminum, Steel

摘要

The suitability of a new Rapid Machining tool for prototyping components out of a variety of metal powders was investigated. A high power laser is aimed at a substrate and material powder is supplied to the interaction zone. By translating the substrate in XYZ direction 3D geometries were created.A high power CO_2 laser was used as energy source, the material powders under investigation were Copper, Ti-6Al-4V, Aluminum, and Stainless Steel SS304 (particle size 100 μm). Helium was used as shield gas. The incident CO_2 laser beam power was varied between 300 W and 400 W, with the laser beam intensity distributed in a donut mode of 600 μm diameter.Metal vapor/plasma plume spectra were recorded using a Photonic Multi-Channel Analyzer, covering the spectrum from 300 nm to 800 nm. Plume temperatures for all materials were calculated to be in the range from 5900 K to 6200 K which is well below ionization temperature (8000 K). The metal vapor/plasma plume is classified as a weakly ionized plasma.