System and Method for Controlling Powder Bed Density for 3D Printing

Patent metadata

Field	Value
Publication number	US-2019193150-A1
Application number	US-201816166968-A
Country	US
Kind code	A1
Filing date	Oct 22, 2018
Priority date	Dec 26, 2017
Publication date	Jun 27, 2019
Grant date	—

Abstract

A system and corresponding method for additive manufacturing of a three-dimensional (3D) object to improve packing density of a powder bed used in the manufacturing process. The system and corresponding method enable higher density packing of the powder. Such higher density packing leads to better mechanical interlocking of particles, leading to lower sintering temperatures and reduced deformation of the 3D object during sintering. An embodiment of the system comprises means for adjusting a volume of a powder metered onto a top surface of the powder bed to produce an adjusted metered volume and means for spreading the adjusted metered volume to produce a smooth volume for forming a smooth layer of the powder with controlled packing density across the top surface of the powder bed. The controlled packing density enables uniform shrinkage, without warping, of the 3D object during sintering to produce higher quality 3D printed objects.

First claim

1 - 30 . (canceled)

31 . A binder jet system for additive manufacturing of a three-dimensional object, the system comprising:
a hopper configured to deposit an amount of powder material onto a powder print bed; an adjustment apparatus configured to adjust a height of the amount of powder material on the powder print bed; a spreading apparatus configured to spread the amount of powder material across the powder print bed to form a layer; and a print head configured to deposit a fluid to bind at least one region of the layer of powder material.

32 . The system of claim 31 , wherein the adjustment apparatus is configured to remove at least a portion of the amount of powder material from the powder print bed.

33 . The system of claim 32 , wherein an intended height of the powder material is predetermined and the adjustment apparatus is configured to remove at least a portion of the amount of powder material that causes the amount of powder material to exceed the predetermined height.

34 . The system of claim 31 , wherein the adjustment apparatus is positioned between the hopper and the spreading apparatus.

35 . The system of claim 31 , wherein the adjustment apparatus is configured to remove at least a portion of the amount of powder material that exceeds a target height from the powder print bed.

36 . The system of claim 35 , wherein the adjustment apparatus is further configured to direct at least a portion of the removed powder material into a container separate from the powder print bed.

37 . The system of claim 36 , wherein the container is operably coupled to the hopper.

38 . The system of claim 36 , wherein the powder material is a metal powder material, and wherein the container is a blender configured to blend the removed metal powder material with another amount of metal powder material.

39 . The system of claim 32 , wherein the adjustment apparatus comprises a skimming device configured to skim the amount of powder material to remove at least a portion of the powder material from the powder print bed.

40 . The system of claim 39 , wherein the skimming device includes a narrowed edge portion that is oriented to contact the amount of powder material to remove the at least a portion of the powder material that exceeds a target height from the powder print bed.

41 . The system of claim 35 , wherein the adjustment apparatus comprises a roller configured to rotate about an axis.

42 . The system of claim 41 , wherein the roller is configured to rotate about the axis in a direction such that a portion of the roller closest to the powder print bed rotates in a direction opposite to a direction of travel of the roller.

43 . The system of claim 41 , wherein the axis of the roller is angled at a non-perpendicular angle relative to a direction of travel of the roller across the powder print bed.

44 . The system of claim 35 , wherein the adjustment apparatus includes a vacuum device configured to apply suction to the amount of powder material to remove the at least a portion of the powder material.

45 . The system of claim 44 , wherein the vacuum device comprises a roller with one or more vents configured to apply the suction to the amount of powder material to remove the at least a portion of the powder material through the one or more vents.

46 . The system of claim 31 , further comprising a roller positioned ahead of the spreading apparatus relative to a direction of travel of the spreading apparatus across the powder print bed.

47 . The system of claim 46 , wherein the roller positioned ahead of the spreading apparatus is configured to traverse the powder print bed in the direction of travel of the spreading apparatus, and wherein the roller is configured to rotate around an axis in a direction such that a portion of the roller closest to the powder print bed rotates in a direction opposite to the direction of travel.

48 . A binder . et system for additive manufacturing of a three-dimensional object, the system comprising:
a hopper configured to deposit an amount of powder material onto a powder print bed; a skimming device configured to traverse the amount of powder material to remove excess powder material from the powder print bed; a spreading apparatus configured to spread the powder material to form a layer of the powder material across the powder print bed; a printing apparatus configured to deposit a fluid to at least one region of the layer to bind the powder material in the at least one region of the layer; and a controller configured to control one or more of the hopper, the skimming device, the spreading apparatus, or the printing apparatus.

49 . The system of claim 48 , wherein the skimming device includes a narrowed edge portion positioned to contact the amount of powder material as the skimming device traverses the powder print bed to remove at least a portion of the excess powder material to adjust a height of the amount of powder material on the powder print bed.

50 . The system of claim 48 , wherein the skimming device is positioned between the hopper and the spreading apparatus relative to a direction of travel across the powder print bed.

51 . The system of claim 48 , further comprising at least one vacuum device configured to apply suction to the amount of powder material to remove the excess powder material.

52 . The system of claim 51 , wherein the at least one vacuum device comprises a first vacuum device and a second vacuum device, wherein the first vacuum device is positioned upstream of the skimming device relative to a direction of travel across the powder print bed, and wherein the second vacuum device is positioned downstream of the skimming device relative to the direction of travel across the powder print bed.

53 . The system of claim 48 , wherein the powder material is a metal powder material, wherein the skimming device is further configured to direct the excess metal powder material into a container that is operably coupled to the hopper, and wherein the container is configured to blend the excess metal powder material removed from the powder print bed with another amount of metal powder material.

54 . A binder . et system for additive manufacturing of a three-dimensional object, the system comprising:
a hopper configured to deposit metal powder material onto a powder print bed; a roller positioned downstream of the hopper relative to a direction of travel of the hopper across the powder print bed, wherein an axis of rotation of the roller is angled at a non-perpendicular angle relative to the direction of travel; and a print head configured to deposit a fluid to at least one region of the metal powder material to bind the metal powder material in the at least one region.

55 . The system of claim 54 , wherein the roller is configured to at least one of spread or compact the metal powder material as the roller traverses the powder print bed.

56 . The system of claim 54 , wherein the non-perpendicular angle of the roller is configured to direct at least a portion of the metal powder material off the powder print bed.

57 . The system of claim 56 , wherein by directing the at least a portion of the metal powder material off the powder print bed, the roller reduces a height of the metal powder material on the powder print bed.

58 . The system of claim 56 , further c

Assignees

• Desktop Metal Inc

Inventors

• Hudelson George
• Sachs Emanuel M
• Jordan Glenn A
• Zero Midnight

Classifications

• B22F3/004 Primary

  Filling molds with powder (feeding material to presses in general B30B15/302) · CPC title

• B22F10/37

  of powder bed aspects, e.g. density · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F10/14

  by jetting of binder onto a bed of metal powder · CPC title

• B22F12/52

  Hoppers · CPC title