Solid-Liquid-Vapor Phase Change of a Subcooled Metal Powder Particle Subjected to Nanosecond Laser Heating

Abstract

Solid-liquid-vapor phase change of a metal particle subjected to nanosecond pulse laser heating is investigated analytically. Temperature distribution in the particle, locations of solid-liquid and liquid-vapor interface, saturation temperature, and recoil pressure around the particle were obtained analytically. Effects of physical parameters including laser fluence, pulse width, initial temperature, and particle diameter on the phase change were investigated. The results show that a decrease in particle radius and laser pulse width, or an increase in laser fluence and initial particle temperature, results in an earlier melting time, a higher surface temperature, more evaporated material, and a higher final thermalized temperature.

KEY WORDS:

• melting
• solidification
• evaporation
• laser

Support for this work by the Office of Naval research (ONR) under grant number N00014-04-1-0303 and by the University of Missouri Research Board is gratefully acknowledged.

Chad Konrad is currently at Buro Happold, 105 Chambers St., 3rd Floor, New York, NY 10007.

Notes

5. D.E. Bunnell, Fundamentals of Selective Laser Sintering of Metals, Ph.D. dissertation, University of Texas at Austin, Austin, TX, 1995.