Mixing device for producing a powder mixture

A mixing device for producing a powder mixture of a first powder component and at least one second powder component for an additive manufacturing device in which a three-dimensional object can be produced by layer-wise selective solidification of a building material comprising the powder mixture, the mixing device comprising:

• a first container for receiving the first and/or the second powder component, wherein the first container provides a discharge opening for discharging the first and/or the second powder component at a bottom of the first container;
• a second container for receiving the first and/or the second powder component;
• and
• a powder conduit that connects to the discharge opening of the first container and is guided into the second container,
• wherein the second container is designed to be at least partially open towards an upper side;
• and
• wherein the first container comprises at least one fluidization zone for introducing a gas into the first container, the at least one fluidization comprising a cavity and a porous plate or a grid for passing the gas from the cavity into the first container.

A mixing device for producing a powder mixture of a first powder component and a second powder component for an additive manufacturing apparatus producing objects by layer-wise solidification of the powder mixture, the mixing device comprising:

• a first container and a second container, the first container having a first container interior receiving the first powder component;
• the second container having a second container interior receiving the second component;
• a mixing conduit connecting the first and second container interiors, the mixing conduit extending from a first outlet in a bottom of the first container interior to the second container interior;
• a drive moving powder through the mixing conduit;
• a fluidizing mechanism communicating with the second container interior, the fluidizing mechanism percolating gas through first and second powder components in the second container interior to intermingle the first and second powder components;
• a second outlet in a bottom of the second container interior;
• a first valve opening and closing the first container outlet;
• a second valve opening and closing the second outlet, the second valve communicating with the first container interior;
• and
• a third valve located in the mixing conduit, the third valve having a mixing position wherein powder material flows through to the second container interior, and a mixed powder transfer position wherein mixed powder material is transferred out of the mixing device.