Method and apparatus for continuously refreshing a recoater blade for additive manufacturing

Abstract

The present disclosure generally relates to additive manufacturing systems and methods involving a mechanism for feeding in a desired amount of fresh recoater blade. This can be accomplished by, for example, spooling the fresh blade material from a spool. This helps prevent work stoppage when a portion of a recoater blade becomes damaged. As such, the present disclosure also relates to a system and method for detecting whether a recoater blade is damaged, and if there is damage, then causing a fresh blade portion to be fed in.

Claims

1. A method for fabricating a desired object, comprising: (a) passing a recoater arm comprising a continuous integral feed recoater blade over a powder bed to provide a layer of powder over the powder bed; (b) irradiating at least part of the layer of powder in the powder bed to form a fused region of an object; (c) repeating steps (a) and (b) until the desired object is formed in the powder bed; and (d) feeding, from a feed unit to the recoater arm, a new blade portion of the continuous integral feed recoater blade along at least a portion of a length of the recoater arm for replacing a blade portion of the continuous integral feed recoater blade with the new blade portion; wherein the method for fabricating the desired object further comprises detecting whether the blade portion or the object is damaged, via a camera attached to the recoater arm.

2. The method for fabricating the desired object according to claim 1, wherein feeding a new blade portion occurs before, during, or after forming the object.

3. The method for fabricating the desired object according to claim 1, wherein the blade portion is made of silicone rubber.

4. The method for fabricating the desired object according to claim 1, wherein the blade portion is made of plastic.

5. The method for fabricating the desired object according to claim 1, wherein the blade portion is made of the same material as the powder.

6. The method for fabricating the desired object according to claim 1, further comprising detecting whether the object is damaged.

7. The method for fabricating the desired object according to claim 1, further comprising feeding a new blade portion if the blade portion is damaged.

8. The method for fabricating the desired object according to claim 1, wherein feeding a new blade portion is accomplished by spooling the new blade portion.

9. The method for fabricating the desired object according to claim 8, wherein spooling the new blade portion is accomplished using at least one payout spool unit.

10. The method for fabricating the desired object according to claim 8, wherein spooling the new blade portion is accomplished using at least one takeup spool unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a powder bed containing an object made by an additive manufacturing process according to the prior art.

(2) FIG. 2 is a schematic view of a conventional powder bed additive manufacturing process using a recoater arm to distribute powder in a horizontal fashion over a build plate.

(3) FIG. 3 is a schematic view of a conventional additive manufacturing apparatus using a hopper to distribute powder over a build plate.

(4) FIG. 4 is an illustration of a recoater arm with a recoater blade according to the prior art.

(5) FIG. 5 is an illustration of a recoater arm with an arm portion and blade portion, and takeup/payout spools according to an embodiment of the invention.

(6) FIG. 6 is a powder bed containing an object made by an additive manufacturing process according to an embodiment of the invention.

DETAILED DESCRIPTION

(7) The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced.

(8) In an embodiment, the invention relates to methods of making a desired object by additive manufacturing, including steps of distributing a portion of powder over a build plate by spreading the powder with a recoater arm comprising an arm portion and a blade portion, focusing an energy beam to make a fused region, repeating until the desired object is formed, and feeding in fresh blade material at least once during the process. The powder is preferably a metallic alloy, polymer, or ceramic powder. Unused powder can be collected in a powder receptacle, and recycled if desired. The portion of powder may be provided by, for example, depositing the powder via a hopper. The step of focusing an energy beam can be accomplished with, for example, a laser or an electron beam apparatus such as an electron gun.

(9) In an embodiment, the invention relates to methods of making a desired object by additive manufacturing, including distributing a portion of powder over a build plate by spreading the powder with a recoater arm comprising an arm portion and a blade portion, focusing an energy beam to make an object, feeding new blade material, and repeating until the desired object is formed. Feeding new blade material can be accomplished by, for instance, spooling the fresh blade material into the recoater arm using a payout spool and/or a takeup spool. In one aspect, the presently disclosed method includes checking if either the object or the blade is damaged. In another aspect fresh blade material is fed into the recoater arm if the blade portion is damaged. In another aspect, used blade material may be collected if desired. Blade material can be collected by, for instance, depositing the blade material in a blade material receptacle, or by collecting it in a takeup spool. The step of checking whether the blade or the object is damaged can be performed by any means capable of inspecting the blade or object, for instance using a camera. The camera may transfer data to a computer.

(10) In an embodiment, the invention relates to an apparatus for making a desired object by additive manufacturing comprising a powder bed area around a build plate, an energy directing device, a recoater arm with an arm portion and a blade portion, and a blade material feed unit. The blade portion may be made of a material such as silicone rubber, plastic, or a material suitable for making an object by DMLM. The energy directing device may be, for example, a laser or an electron beam. The blade material feed unit may be, for example, a payout spool. The apparatus may further comprise a blade material receiving unit. The blade material receiving unit may be, for example, a takeup spool or a blade material receptacle.

(11) In an embodiment, the invention relates to an apparatus for making a desired object by additive manufacturing comprising a powder bed area around a build plate, an energy directing device, a system for checking if either the recoater blade or the part is damaged, and a recoater arm with an arm portion and a blade portion. The system for checking if either the recoater blade or the part is damaged may be any system capable of visually inspecting the recoater blade or part, for instance a camera. The camera may transfer data to a computer.

(12) FIG. 1 shows an exemplary prior art system for DMLM 100. The part 122 is built layer-by-layer by sintering or melting powder material in the shape of a layer of the object. The sintering or melting is performed using an energy beam 136 generated by an energy source such as a laser 120 and controlled by a galvo scanner 132. The powder to be melted by the energy beam is supplied by a reservoir 126 and then spread evenly over a build plate 114 using a recoater arm 116 traveling in a direction 134 to maintain the powder at a level 118 and remove excess powder material extending above the powder level 118. Some of the excess powder material is deposited in waste container 128. Then the build plate 114 is lowered and another layer of powder is spread over the build plate and the object being built, powder material is melted or sintered by the laser 120, and the process is repeated until the part 122 is complete.

(13) FIG. 2 shows powder bed for additive manufacturing according to the prior art. A powder dispenser 201 is provided that pushes an amount of powder (e.g., CoCr) upward into the build chamber where a roller or arm 202 spreads the powder over the build plate 203. A laser heats the powder in a desired pattern corresponding to a cross section of a part, sintering or melting the powder to form a solid cross section slice on the build plate 203. The build plate is lowered and the powder dispenser and roller or arm redistributes a thin layer of powder over the build plate. The laser then heats the powder building on the earlier deposited pattern of fused material, thereby making successive layers in the additive manufacturing process.

(14) FIG. 3 shows a powder bed and recoating system for additive manufacturing according to the prior art. A powder hopper 301 used in conjunction with a recoater arm/temporary hopper 302. The recoater arm/temporary hopper 302 spreads a thin layer of powder over the build plate 303 by moving across the build plate and dropping powder in a controlled manner to provide a thin layer of powder. This process is repeated with each laser writing step and lowering of the build plate in the additive manufacturing process.

(15) FIG. 4 shows a recoater arm for use in an additive manufacturing process according to the prior art. There is a recoater arm 400 with a single use recoater blade 401 and powder 402.

(16) FIG. 5 shows a recoating system 500 with recoater arm 501 and a continuous feed recoater blade 502 according to an embodiment of the invention. The recoating system in FIG. 5 has a payout spool 503 and a takeup spool 504. The recoater blade 502 is fed in a direction 505. The recoater blade 502 is moved in a direction 506 to provide a substantially even layer of powder.

(17) FIG. 6 shows an exemplary additive manufacturing system with a continuous feed recoater blade according to an embodiment of the invention. The part 622 is built layer-by-layer by sintering or melting powder material in the shape of a layer of the object. The sintering or melting is performed using an energy beam 636 generated by an energy source such as a laser 620 and controlled by a galvo scanner 632. The powder to be melted by the energy beam is supplied by a reservoir 626 and then spread evenly over a build plate 614 using a recoater arm 616 with a continuous feed recoater blade traveling in a direction 634 to maintain the powder at a level 618 and remove excess powder material extending above the powder level 618. Some of the excess powder material is deposited in waste container 628. Then the build plate 614 is lowered and another layer of powder is spread over the build plate and the object being built, powder material is melted or sintered by the laser 620, and the process is repeated until the part 622 is complete. There is also a camera 638 attached to the recoater arm that is capable of transferring data to a computer 640, which allows for detection of whether the object or the continuous feed recoater blade becomes damaged.