In solid freeform fabrication (SFF) processes involving thermal deposition, thermal control
of the process is critical for obtaining consistent deposition conditions and in limiting residual
stress-induced warping of parts. In this research, nondimensionalized plots (termed process maps)
are developedJrom numerical models of laser-based material deposition of thin-walled structures
that.map out the effects of changes in laser power, deposition speed and part preheating on process
parameters. The principal application of this work is to the Laser Engineered Net Shaping (LENS)
process under development at Sandia Laboratories; however, the approach taken is applicable to
any solid freeform fabrication process involving. a moving heat source. Similarly, although thinwalled structures treated in the current work, the same approach could be applied to other
commonly fabricated geometries. A process map for predicting and controlling melt pool size is
presented .and numerically determined results are compared against experimentally measured melt
poollengthsfor stainless steel deposition in the LENS process.Mechanical Engineerin
