Stable layer-building strategy to enhance cold-spray-based additive manufacturing

Cold spray (CS) has recently become one of the popular additive manufacturing (AM) processes for its advantages: high-forming efficiency, low temperature, and no phase changing of materials. These advantages may make CS able to form large volume objects and possibly directly iterate with material-removing processes to become a hybrid AM process. Current research proposes using a bulk-based volume-forming strategy (e.g. a tessellation-based method) for volume building. Although it can form 3D volumes, the control of the process is difficult and it has limitations in forming complex 3D near-net-shapes with acceptable accuracy. This also conflicts with the basic principle of AM, where the volume forming is via the manner of layer by layer. To solve this problem for easy process control, this paper proposes a new spray strategy, one that considers the characteristics of cold spray and kinematic parameters, to enhance stable layer building for 3D shape forming. Both simulation and experiments are conducted for method verification. The benchmarking test on some basic objects shows better shape accuracy than existing methods, and the proposed process is easier to control, repeat and follow. This implies that the proposed method makes CS a real and ready layer-by-layer AM process for 3D shape forming.