Modeling of Selected SFF Process Limits

An analytical model of the thermal field for one scan line during SLS is developed. Quantitative relationships between net heat input and beam velocity are stated for sintering at a given distance from the center of the beam and for the case of maximum surface temperature. For the maximum surface temperature, two extreme cases have been analyzed: pure conduction heat transport, and highly convective molten consolidation. It is suggested that a highly convective process allows significantly higher net heat input than pure conduction. It is found that for certain conditions, the relationship between net heat input and beam velocity is independent of the thermal conductivity of the material. Key Words: model, melting, selective laser sintering, thermal, process window.