Abstract

Melting and resolidification of a mixture of two metal powders with significantly different melting points under irradiation of a stationary or a moving Gaussian laser beam were investigated numerically and experimentally. The liquid motion driven by capillary and gravity forces as well as the shrinkage of the powder bed caused by the overall density change were taken into account in the physical model. The liquid flow was formulated by using Darcy’s law, and the energy equation was given using a temperature transforming model. Prediction were compared with experimental results obtained with nickel braze and AISI 1018 steel powder. The effects of laser properties and the scanning velocity on the laser sintering process were also investigated. An empirical correlation that can be used to predict the cross-sectional area of the heat affected zone is proposed. [S0022-1481(00)70201-5]

Issue Section:
Heat Transfer in Manufacturing
Keywords:
sintering, powder metallurgy, heat transfer, manufacturing processes, solidification, melting, laser materials processing, Heat Transfer, Laser, Manufacturing, Melting, Solidification
Topics:
Laser beams, Lasers, Melting, Melting point, Metal powders, Sintering, Temperature, Particulate matter, Density, Irradiation (Radiation exposure), Solidification, Manufacturing, Brazing, Nickel, Shrinkage (Materials), Flow (Dynamics), Gravity (Force)
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