Additive manufacturing technology of investment casting

In recent years, a lot of new processes and technologies have emerged, which have formed a strong competition for investment casting technology in material preparation, rapid response of products, low-cost batch manufacturing, structural and functional gradient integrated manufacturing, etc. However, the new process and the old process always complement each other, promote each other, and cannot be completely replaced. How to promote the technological transformation of the old process with the help of the new process and new technology, It is an opportunity and challenge for researchers.

Investment casting has great advantages in the complexity of parts and material adaptability, but its flexibility is poor. The preparation of the mold often requires a certain period. The change of the structure and size of investment casting often directly affects the long and complex process of the design, manufacture, assembly and other processes of the mold (including the mold). Additive manufacturing is an advanced manufacturing technology with high flexibility. Through the mathematical model of product design, the material is stacked and accumulated to complete the production of parts. With the help of the programming input of the mathematical model, the liquid or adhesive materials such as metal powder, wire and plastic particles are used to construct the solid layer by layer. In addition to printing additive manufacturing equipment, other tooling and tools are not required, and the material utilization rate is very high, It can effectively shorten the processing cycle, combine the additive manufacturing technology with investment casting technology, and use the additive manufacturing technology to manufacture the mold or parts, which can greatly improve the flexibility of investment casting, accelerate the production and development of investment casting, meet the task of new product trial production and small batch production, and complement and promote each other with investment casting. At present, the additive manufacturing technologies that can be used to directly manufacture metal structural parts mainly include: selective laser melting SLM, electron beam selective melting EBSM, and laser near-net forming LENS.