The research hotspots of 3D printing are currently focused on materials and equipment. 3D printing of organic polymer materials such as engineering plastics and photosensitive resins and metal materials such as aluminum alloys, copper alloys, titanium alloys, and stainless steels has been obtained. Great progress. From the working principle of 3D printing technology, it can be seen that its molding powder needs to have the advantages of good material molding, small powder size, not easy to agglomerate, good fluidity, fast drying and hardening, etc. However, due to its own characteristics (brittle, high melting point), ceramic materials There are still many difficulties to be overcome in 3D printing. At present, ceramic materials for 3D printing mainly include aluminum silicate, alumina, zirconia and calcium phosphate. Usually, ceramic powder and photosensitive resin (binder powder) are mixed to make available. 3D printed materials. 3D printed ceramics have the following difficulties to be overcome:
1. The ratio of ceramic powder and binder powder will affect the performance of ceramic parts. The more the binder content, the easier the curing, but the parts shrink during the post-processing, which affects the dimensional accuracy of the parts.
2. The melting point of photosensitive resin is low, and the liquid resin has high viscosity, which results in poor fluidity. It is difficult to smooth the liquid surface in a short time after each layer is cured, which will affect the molding accuracy of the entity.
3. When the ceramic powder is directly sintered by laser, the surface tension of the liquid phase is large, and a large thermal stress will be generated during the rapid solidification process, thereby forming more micro-cracks.
4. Accuracy and efficiency, as parts of mechanical engineering, the accuracy and surface smoothness of the finished 3D printing products are currently not up to the requirements. In addition, after the accuracy is extremely high, the problem it will inevitably bring is that the efficiency will be relatively low. So how to print the finished product quickly and well, it is still necessary to improve and study.
V. Development prospects of ceramic 3D printing
The current largest customer base for the 3D printed ceramics market comes from the aerospace and defense high-tech industries. Both of them have a large demand for ceramic products (such as thermal insulation tiles for spacecraft); followed by the biological health medical field, ceramics in this field It is mostly used in the manufacture of medical products like dentures, surgical instruments, human prostheses, implants, etc., because 3D printing technology can accurately customize medical products for patients to fit their own body structure, and the biological compatibility is very good. Because the preparation of 3D printed ceramic paste is difficult, the ratio of ceramic powder to binder, pH value, particle size and rheology of the paste all have a great impact on the performance of ceramic products, so the application of this technology Maturity also needs to be effectively improved. Ceramic 3D printing technology has irreplaceable advantages over traditional technology. I believe that with the continuous improvement of this technology, the application of 3D printing technology in the field of ceramics will become more and more extensive.