Production of Metallic and Ceramic Parts with the Optoform Process

摘要

Optoform LLC developed a technology to process paste compositions based upon photo-curable resins and fillers. This new process is called by Optoform LLC : the direct composite manufacturing. At the present time, about ten alpha machines have been sold in USA and Europe to set up a collaboration between material developers, process developers and end users. This technique is quite flexible and allows the development of very different material for many different applications. Mainly, four categories of material have been developed, namely soft material, hard material, metallic and ceramic material. Both last kinds will be the main purpose of this presentation. Metal (316L, 17- 4 PH, Titanium) or ceramic (Zircon/Silica, alumina, hydroxyapatite) powders form about 60 % (in volume) of a pasty photo-curable material. After the building of the prototype on the Optoform machine, a post-processing is required consisting of a debinding and sintering steps. The debinding consists of removing the resin binder by an appropriate thermal treatment. The debinding parameters are a function of the organic phase and of the powder nature. After that, the part is sintered in order to produce a full dense part and to enhance the mechanical properties. It is also possible to manage a partial sintering to obtain porous parts which can be used when an auto lubricating is needed. The bimodal distributions of powder and the particle size will be discussed in relationship with the sintering parameters and with the effect on the mechanical properties. This new process is a development station for new broad range of rapid prototyping (RP) materials and it represents one more step toward the Rapid Manufacturing of high technical parts. The Optoform process was well adapted to a broad range of applications for parts as well as for shells or investment casting cores.