3. One-time conversion method
The one-time conversion method, as its name suggests, is a further product that needs to be further integrated with other manufacturing processes through rapid prototyping. The rapid prototyping technique is usually performed on a master mold and then combined by different processes such as sand casting, investment casting, and vacuum casting to obtain the final metal part. This process is generally suitable for small batch parts or for single piece production. Here are a few different ways to elaborate.
First, rapid prototyping technology for sand casting molds. First, the resin material is selected to be molded by rapid prototyping technology, and then sprayed or gold-plated to obtain a more accurate prototype. The prototype can then be mounted to a core box or template for production processing. The specific steps are as follows: Firstly, the professional auxiliary software is used to set a certain margin for the machined parts, as well as the draft and round corners. Then by passing these geometric data into the system, you can get the corresponding slightly modified part pattern. Then these patterns are spliced to form a template. If the pattern is large, it can also be made by sub-modules, and finally assembled to form a complete prototype. Usually the back side of the pattern can be designed as a honeycomb structure, which on the one hand can reduce the use of materials and on the other hand can save time on the machine. The honeycomb structure design should be designed according to the bearing pressure standard of the model. In addition, in order to effectively improve the wear resistance of the model, it is necessary to perform aluminum alloy plating on the surface or spray Teflon plastic.
Second, casting investment rapid prototyping technology. This technology enables the rapid manufacture of ceramic shells through auxiliary design software and three-dimensional molding equipment, which can save time in investment casting, such as wax molds and press molding. Moreover, this ceramic shell model can completely ignore the factors of wax mold deformation, so it can improve the precision of the parts, and can also produce hollow parts.
Third, casting lost foam rapid prototyping technology. This process is mainly for rapid prototyping by forming a resin such as a three-dimensional printing SLA and a melt-forming FDM, and a thermoplastic material. The formed pattern is then coated with refractory material and placed in a sealed, sand-filled enclosure. The air in the tank is then pumped out to create a vacuum environment that will allow the sand to become tighter. At this time, the molten metal is injected into the sand mold through a special pouring port, and then the pattern is burned off, so that the metal part can be obtained. If the conventional method of burning out is less effective, the selective laser sintering mode and PMMA powder can be used to construct the pattern, which can effectively avoid the gray traces that may be left by the burnout pattern.