This conference paper was submitted for presentation at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

The process of powder bed fusion (PBF) is becoming well-established within the manufacturing industry. Although this manufacturing process can produce components that would otherwise be too difficult or sometimes even impossible to produce with conventional manufacturing processes, it still has challenges that need to be circumvented or solved before it may become more widely used throughout industry. The problems associated with PBF are usually categorised as manufacturing process or structural integrity problems. One very effective tool in addressing and resolving such problems is the finite element analysis (FEA). This numerical tool can reveal information and uncover trends of behaviour that would otherwise remain hidden. It has its own challenges, however, as it inherently relies on making assumptions and simplifications, which at times may compromise the accuracy or validity of the numerical outcome. It is important therefore to apply FEA correctly and effectively. Whether PBF is achieved through laser or electron beam application, the process can be modelled using the same approach in FEA. The process of metallic PBF entails the deposition of many layers of metal after sequentially melting the powder and allowing it to solidify to form the layers precisely, producing the desired component shape. This can be modelled in FEA by two different methods. One method involves modelling the deposition of the layers by activating the mesh elements of the numerical model that correspond to the metal as it is being deposited; hence, it is a gradual and sequential procedure of element activation. The other method is to alter the material properties of the metal to reflect the formation of the liquid and then the solid material from the original powder state; hence, it is also a gradual procedure that is in this case governed by the temperature history of the material, which in turn is dictated by the movement of the heat source. Both of these numerical methods have their own advantages and drawbacks. In this reported research, the two methods are described and compared by generating and simulating corresponding thermal FEA models of a cuboid made of an aluminium alloy with a single pass of deposited metal along the top. The advantages and challenges of each method are presented and explained, including degrees of numerical accuracy and stability. Conclusions are also made that can help in making the right choice when modelling is applied to the process of PBF.