Rapid calculation of part scale residual stress-Powder bed fusion of stainless steel, and aluminum, titanium, nickel alloys

摘要

A novel analytical model is developed to compute the part scale through-thickness longitudinal residual stress distributions and applied for laser powder bed fusion of four commonly used powder alloys. An important input for the analytical modeling calculations is the peak residual stress for a deposited layer, which is estimated using a unique functional relationship and presented as a function of important process conditions for laser powder bed fusion of different powder alloys. The analytically calculated results of longitudinal residual stress distributions through the part and baseplate thickness are tested rigorously with the corresponding numerically computed and experimentally measured results in the literature for laser powder bed fusion of small and large parts involving the deposition of several thousands of layers. It is shown further that the analytical model can serve as a fast and practical design tool to estimate the through-thickness longitudinal residual stress distribution, which is along the length of the part, for part scale laser powder bed fusion using inexpensive computational resources and with appreciable accuracy.