Automatic Determination of Part Build Orientation for Laser Powder Bed Fusion Additive Manufacturing

Laser powder bed fusion is one of the key and most widely used additive manufacturing processes. The use of this process to build a part includes a set of continuous activities, where process planning is an indispensable one. This activity refers to a systematic planning of the build orientation, supports, slices, laser scanning path and process parameters to build a part using a laser powder bed fusion machine. It includes four successive steps, where build orientation determination is the first step. At present, most of the determination tasks in real workshops are manually completed by process planners according to their production knowledge and experience. Different process planners could determine different build orientations for an identical part under the same conditions. This would increase the build time and build cost and have a negative influence on the quality and production stability of the built part.

To this end, a study on automatic determination of part build orientation for laser powder bed fusion additive manufacturing is carried out in this thesis. This study divides build orientation determination into alternative orientation generation and optimal orientation selection. Firstly, an automatic alternative orientation generation method based on facet clustering for laser powder bed fusion is presented. A set of fuzzy aggregation operators for evaluating the values of attributes of alternative orientations are then constructed. Using the constructed operators, an automatic optimal orientation selection method based on multi-attribute decision making for laser powder bed fusion is proposed. Finally, an automatic part build orientation determination method for laser powder bed fusion is developed via combining and implementing the alternative orientation generation method and optimal orientation selection method. Case studies are presented to illustrate the application of the developed method. The effectiveness, efficiency and advantages of the method are evaluated via theoretical analysis, experimental analysis and comparisons.

The completed research work in the thesis is expected to realise a transformation of part orientation for laser powder bed fusion from a manual mode to a computer-aided mode. It can easily be extended to other additive manufacturing processes and can provide effective ideas and methodology for study of computer-aided process planning for additive manufacturing.