Cold gas dynamic spraying as a method for freeforming and joining materials

In this study cold gas dynamics spraying (CGDS) was successfully used as a joining process to deposit filler metal between two beveled plates. The technique was also employed to build 3-D freeforms. Verification of conceptual experiments was carried out using conventional zinc feedstock powder. SEM and optical microscopy confirmed that dense deposits were created. No significant difference was observed in the mechanical properties between the freeforms and the weldments. Hardness values of 34 ± 2.5 vs. 33 ± 3.2 HV and bending strength of 127 ± 17 vs. 162 ± 30 MPa were observed, respectively. Examination of the fracture surfaces showed that the strength of the interface is higher than the strength of the freeform itself. The results obtained demonstrate that CGDS will be a viable technique for rapid prototyping or joining assembly for thermally sensitive materials.