Investigation of plasma spectra during selective laser micro sintering Cu‐based metal powder

Abstract

Purpose

This paper aimed to investigate the plasma characteristics of selective laser micro sintering Cu‐based metal powder using spectra method.

Design/methodology/approach

Temporal and time integrating plasma induced during selective laser micro sintering Cu‐based metal powder with a Q‐switched pulsed YAG laser have been detected and analyzed. Boltzmann plot and Stark broadening of the spectra line are utilized to analyze the electron temperature and density, respectively. The influences of the Q‐switching rate and duration on the plasma temperature and electron density have been investigated.

Findings

The results show that the plasma temperature decreases from 9,600 to 9,000 K with the increase of the Q‐switching rate from 5 to 35 kHz if Q‐switching duration of laser is kept at a constant value. The plots of temporal temperature and electron density show that the electron density varies in a faster speed than plasma temperature and the entire expansion process takes about 700 ns‐1 μs in this experiment. Evolutional images of the plasma plume using Q‐switching rate of 5 kHz and 5 μs have been registered by the ICCD with a 10 ns exposure time, which shows that the plasma plume takes about 100 ns to get to the maximum size and 600 ns to disperse.

Originality/value

The plasma spectra of selective laser micro sintering Cu‐based metal powder have been diagnosed experimentally. The plasma characteristics of selective laser micro sintering Cu‐based metal powder have been analyzed.

Citation

Cheng, D., Zhu, H. and Ke, L. (2013), "Investigation of plasma spectra during selective laser micro sintering Cu‐based metal powder", Rapid Prototyping Journal, Vol. 19 No. 5, pp. 373-382. https://doi.org/10.1108/RPJ-12-2011-0125