First, the current work in materials is mainly: 1. Develop a variety of three-dimensional printing materials that meet the requirements of different uses, such as three-dimensional printing materials for directly forming metal parts and medical, active three-dimensional printing materials. 2. Establish a performance database of materials to develop 3D printed materials with superior performance and pollution-free performance. 3. Using the computer to simulate and analyze the molding process and molding performance of the material. Second, the classification of three-dimensional printing materials 1.SL process molding materials: photosensitive resin composite materials 2. SLS process molding materials: polymer powder materials, paraffin powder materials, ceramic powder materials, coated sand powder materials, plastic powder materials, metal powder material. 3.LOM process molding materials: ceramics, paper 4.FDM process materials: fuse wire, FDM ceramic materials, wood-plastic composite materials, FDM support materials 5.3DP process materials: plastic materials, metal materials, ceramic materials, three, how to choose material? How to choose the model that suits you usually has the following considerations: cost, appearance, detail, mechanical properties, mechanical properties, chemical stability, and special application environment. Although there are various factors, the purpose of model-based production can be roughly divided into two categories: appearance verification model and structure verification model. Appearance Verification Model: A hand model designed by an engineer to verify the appearance of a product or a model that is directly used and requires a high appearance. The visual verification model is visual and touchable. It can intuitively reflect the designer's creativity in the form of physical objects, avoiding the drawbacks of “painting good looks and making them look bad”. The appearance verification model is indispensable in the process of new product development and product shape. Based on the requirements of the appearance verification model, it is recommended to use 3D printing of photosensitive resin (including high-precision and tough ABS and transparent PC materials); structural verification model: in the product design process, from design to mass production, it is generally required to make molds. The cost of mold manufacturing is very high. The relatively large mold value is hundreds of thousands or even millions. If the structure is unreasonable or other problems are found during the mold opening process, the loss can be imagined. Therefore, the structural verification model can avoid this loss and reduce the risk of mold opening. Based on the requirements of the structural verification model, the accuracy and surface quality requirements are not high. It is recommended to select materials with good mechanical properties and low prices, such as PLA and ABS. In addition, there are some special requirements, such as the need for electrical conductivity, the need for metal materials, or to reverse the production of a fine jewelry, it is recommended to use paraffin. The above materials may not be very comprehensive, you can go to the following website to see, the content is very detailed (how to choose 3D printing materials) Fourth, the requirements of the various materials for the various three-dimensional printing process requirements for its molding materials are generally fast Precisely shaped, the prototype has a certain mechanical function.