| The required rapid cooling has limited the dimension of the Bulk Metallic glasses (BMGs) produced by traditional method, and hence has seriously limited their applications, despite their remarkable mechanical properties. In this present project, a detailed study is conducted on the methodology and understanding of manufacturing large Zr- based metallic glass part by laser based additive manufacturing technology, which breaks the size limitation. The first research issue proposes and develops a new additive manufacturing technology, named Laser-Foil-Printing (LFP). Sheet foils of LM105 (Zr52.5Ti 5Al10Ni14.6Cu17.9 (at. %)) metallic glass are used as feed stork. Fully amorphous 3D structures are successfully achieved. The second research issue focus on investigating the temperature evolution during laser-BMG interaction. By combining experimental measurement and mathematical model, the dynamic temperature field evolution during laser-BMG interaction is simulated. The developed model not only optimizes the LFP process, but also helps us in further understanding the fundamental crystallization mechanism during laser-BMG interaction. The crystalline phase evolution during laser-MG interaction is studied in the third research issue, using the classical nucleation theory (CNT). Combining with the temperature model, the volume fraction of crystallized BMG is calculated. The result successfully explains the observation of crystalline phase within both the fusion zone (FZ) and the heat-affected-zone (HAZ) of laser processed BMG. This thesis is a proven road map for developing metallic glass structures using additive manufacturing technology. The research results of this dissertation can benefit a wide range industry, such as 3D printing, material science, medical and aerospace. |
