Apparatus and method for producing an article by additive manufacturing
The present invention relates to an apparatus for producing an article by additive manufacturing comprising a first container and a second container from which powder may be selectively dispensed to form an article, wherein the first container and the second container contain the same type of powder and wherein the containers respectively contain powder that has been recycled to different extents.
1 . An apparatus for producing an article by additive manufacturing comprising:
a) a first container and a second container from which metal powder may be selectively dispensed in powder form to produce an article, wherein the first container contains a quantity of a non-recycled metal powder or a quantity of a first recycled metal powder and the second container contains a quantity of a second recycled metal powder that has been recycled to a different extent to the first recycled metal powder, and wherein each of the non-recycled metal powder or the first recycled metal powder and the second recycled metal powder are the same type of metal powder, and
b) a control unit configured to control the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder dispensed from the first container and the quantity of the second recycled metal powder dispensed from the second container, wherein the control unit is configured to dispense a greater proportion of the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder when predicted stress in a certain region of the article is higher, and the control unit is configured to dispense a greater proportion of the quantity of the second recycled metal powder when the predicted stress in a certain region of the article is lower.
2 . An apparatus according to claim 1 , wherein the first container and the second container respectively contain the quantity of the first recycled metal powder and the quantity of the second recycled metal powder.
3 . An apparatus according to claim 1 , wherein the apparatus is arranged to dispense the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder from the first container and/or the quantity of the second recycled metal powder from the second container onto a build platform.
4 . An apparatus according to claim 1 , wherein the apparatus is arranged to dispense the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder from the first container and/or the quantity of the second recycled metal powder from the second container directly onto a build platform.
5 . An apparatus according to claim 1 , wherein the apparatus is arranged to dispense the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder from the first container and/or the quantity of the second recycled metal powder from the second container onto a build platform via a third container.
6 . An apparatus according to claim 5 , wherein the third container is configured to enable mixing of the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder dispensed from the first container and the quantity of the second recycled metal powder dispensed from the second container.
7 . An apparatus according to claim 1 , wherein the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder from the first container and/or the quantity of the second metal powder from the second container is dispensed onto a build platform via respective delivery platforms.
8 . An apparatus according to claim 1 , wherein the control unit is configured to vary the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder dispensed from the first container and the quantity of the second recycled metal powder dispensed from the second container for each layer of the article.
9 . An apparatus according to claim 1 , wherein the quantity of the non-recycled metal powder or the quantity of the first recycled metal powder in the first container and the second recycled metal powder in the second container comprises a metal alloy.