Tolerance loss due to residual stress-induced warping is a major concern in solid freeform
fabrication (SFF) processes. An understanding of how residual stresses develop and how they
lead to tolerance loss is a key issue in advancing these processes. In this paper, results are
presented from warping experiments on plate-shaped specimens created by microcasting and
welding processes used in Shape Deposition Manufacturing (SDM). Results from these
experiments give insight into differences between the two processes, the role of preheating and
insulating conditions during manufacture and the influence of deposition path on magnitudes and
distributions of warping displacements. Results are then compared to predictions from two types
of residual stress models. While the models effectively predict warping magnitudes and the effects
of various thermal conditions, they are unable to capture some of the more subtle trends in the
experiments. Results from the experiments and numerical models suggest that a combination of
initial substrate preheating and part insulation can be applied to SDM and similar SFF processes to
limit warping deflections, which is substantially simpler than active control of part temperatures
during manufacture. Results also suggest that 3-D mechanical constraints are important in
achieving precise control of warping behavior in SFF processes.Mechanical Engineerin
