Rapid casting (QC) is a new technology formed by combining SLS, SLA, FDM and traditional casting technology. The application object is mainly the high precision manufacturing of complex structural parts in the fields of mold design, aviation, aerospace, navigation and automobile engine manufacturing. The application of QC technology has not only injected new vitality into the traditional manufacturing industry, but also provided a new market for the traditional, greatly simplifying the manufacturing of complex parts.
The practical application of rapid casting technology at home and abroad is mainly divided into direct casting, one-time conversion and two-time conversion
(1) Direct casting is mainly used in the production of large and low surface quality parts. The working principle is to use the rapid prototyping technology (SLS; DSPC) to make the shell directly, and to carry on the special post-treatment to the shell. Finally, the alloy liquid is poured into the preheated shell to obtain the required metal parts.
(2) One time transformation method is mainly used in the trial production of parts in the early stage of scientific research and the production of small batch parts. Firstly, the prototype of wax pattern was made by using rapid prototyping technology (SLS; SLA, etc.), and then the prototype was combined with traditional casting. Because only one technology transformation was carried out, the required parts were obtained.
(3) The second transformation method is mainly used in the production of large quantities of parts. Firstly, the prototype of wax mold is made by rapid prototyping technology (SLS, SLA, LOM, etc.) as the master mold. Secondly, the soft materials such as wax, silicone rubber, etc. are injected into the surrounding of the master mold to make a set of soft mold. Combining the soft mold with thesuch as precision casting, the required parts are obtained after two or more times of technical transformation from wax mold to metal parts.
Among them, SLS Due to the wide variety of materials available in the forming process, from organic materials and their composites (polystyrene, nylon) to low melting point metal, ceramic powder (silica bonded alumina powder), etc.; due to the low melting point of the materials used, compared with other laser forming processes, the laser energy required is lower, so it has lower energy consumption; when preparing larger parts, it can It can effectively improve the processing efficiency and reduce the weight of parts to a great extent, especially in the field of rapid casting, which provides the possibility for the preparation of large-size parts; in the molding process, adding support has the advantage of easy removal compared with other processes, which greatly reduces the workload of subsequent de support; compared with the traditional mold production process, the structure of parts changes greatly There is no need to change the preparation process and equipment, and the real free manufacturing is realized. For the research and development of new products, the production of single and small batch parts shortens the processing cycle and saves the initial cost. Because of the control of computer, the production process is more convenient and fast [8,9]. Therefore, SLS process has a high application prospect in the preparation of complex parts combined with traditional casting process.