Utilization of Partial Sintering to Avoid the Use of Support Structures in the Direct Metal Laser Sintering Additive Manufacturing Processes

摘要

This invention is focused on a new method of the Direct Metal Laser Sintering (DMLS) additive manufacturing process, which builds metal products layer-by-layer from melting the powder at selective locations. In the conventional DMLS process, during the process of building a downward facing surface of products, such as making a ceiling of a box or the top of a horizontal pipe, commonly a temporary support structure is applied at below to let the new layer of molten metal to rest upon. In this invention, the partially sintered layer (or layers) will be used instead, to form a rigid base for the subsequent molten layer at above to rest upon. The partial sintering is achieved with a reduced heating of laser that the powder reaches a high temperature but still below the melting point. This invention will allow for the elimination of the use of temporary support structures, and the time and effort of adding and removing of the temporary support structures are saved.

主权项

1. A method for making metal products using a Direct Metal Laser Sintering (DMLS) process comprising steps of:
a first step of applying a first layer of powder on a surface; a second step of partial sintering (defined in equation (1)) said layer of powder to construct a support structure, as shown in FIG. 2; a third step of applying a second layer of powder on the partially sintered said first layer of power; a fourth step of melting said second layer of powder, as shown in FIG. 3, and repeating the third and the fourth steps to construct the product, whereby downward facing surfaces of a product can be made without a need to construct a temporary support structure.