Feasibility study of chemical liquid deposition based solid freeform fabrication

The Chemical Vapor Deposition (CVD) process has been used in Solid Freeform Fabrication (SFF) for several years, and it has faced some critical problems in deposition rate, product accuracy and facility cost. To overcome these shortcomings and explore new chemical deposition methods and materials, a new rapid tooling and SFF technique named Chemical Liquid Deposition based Solid Freeform Fabrication (CLD-SFF) is proposed. CLD-SFF can further be sub-divided as Thermochemical Liquid Deposition Based SFF (TCLD-SFF) and Electrochemical Liquid Deposition Based SFF (ECLD-SFF). TCLD-SFF is based on the following experimental fact: when cold (room temperature) liquid reactants are sprayed from a nozzle and come in contact with a hot substrate, the reactants can decompose or react with one another, and then the solid products are deposited on the substrate. By controlling the motion of the nozzle and the spray time, a desired three-dimensional shape of deposited material can be formed through layer-by-layer scanning. In ECLD-SFF a special anode was designed to deposit metallic materials among powder particles on a plate cathode. By controlling the motion of the anode and the current and voltage of the electrical field, a desired three-dimensional part made of connected powder particles can be formed through layer-by-layer scanning. According to our initial experimental results, the feasibility of CLD-SFF is discussed and demonstrated.