What step does an operator perform after shutting the safeguards of a direct metal laser sintering (DMLS) machine and before starting the build process?

Filling the build chamber with an inert gas is a crucial step that operators perform after shutting the safeguards on a direct metal laser sintering (DMLS) machine and before initiating the build process. This is done to create a controlled environment that prevents oxidation of the metal powder during the sintering process. Inert gases, typically nitrogen or argon, help to ensure that there is no reaction with the metal materials, which could compromise the integrity and quality of the final part.

Inert environments are particularly important for metals that can easily oxidize, as the presence of oxygen could lead to defects or undesirable changes in the material properties. By thoroughly purging the build chamber with an inert gas, operators maintain the necessary conditions for successful laser sintering.

The other steps, while important, typically occur at different stages or do not directly follow the shutting down of safeguards. Heating the build chamber is essential for preparing the environment for buildup but usually occurs before the inert gas is introduced. Adding support structures is part of the design preparation and is typically done before the actual build process starts. Calibrating the laser is an important setup task, but it is generally performed during the machine preparation phase and not immediately after shutting safeguards.