Method for additive manufacturing

Patent metadata

Field	Value
Publication number	US-12036731-B2
Application number	US-202117243819-A
Country	US
Kind code	B2
Filing date	Apr 29, 2021
Priority date	Apr 21, 2015
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

Various embodiments of the present invention relate to a method of using of a focus lens in additive manufacturing for forming a three-dimensional article through successive fusion, with a high energy beam, of parts of at least one layer of a powder bed provided on a work table, which parts correspond to successive cross sections of the three dimensional article, said method comprising the step of: using said focus lens for varying a spot size of said high energy beam on said powder bed as a function of an already fused thickness of said three-dimensional article below said powder which is to be fused. The invention is also related to a method for forming a three dimensional article.

First claim

The invention claimed is:

1. A method of using at least one means of altering a spot size of a high energy beam in an additive manufacturing apparatus for forming a three-dimensional article through successive fusion of parts of at least one layer of powder material provided on a work table, which parts correspond to successive cross sections of the three-dimensional article, said method comprising the steps of:
providing a deflection source for deflecting the high energy beam on said powder material to provide a protracted beam spot movable over an intended scanning path in a scanning direction used for fusing said powder material;
using said at least one means to vary a Full Width Half Maximum (FWHM) of said high energy beam only if an already fused thickness of said three-dimensional article below said layer of powder material which is to be fused is less than a predetermined thickness; and
wherein a mean spot size of the protracted beam spot in a direction perpendicular to the scanning direction is smaller than a mean spot size of the protracted beam spot in a direction parallel to the scanning direction for a full scan length, a full cross section, and/or for a full 3-dimensional article.

2. The method according to claim 1 , wherein said thickness of said three-dimensional article is the thickness directly below a spot of said high energy beam on said layer of powder.

3. The method according to claim 1 , wherein said thickness is a total number of powder layers which have been fused.

4. The method according to claim 1 , wherein said thickness is the uninterrupted total number of powder layers which have been homogenously fused together.

5. The method according to claim 1 , wherein said means for altering said FWHM of said high energy beam is selected from at least one of the group consisting of: a focus lens, an astigmatism lens, a vacuum level, a grid potential of an electron beam source, or an aperture size of a laser beam source.

6. The method according to claim 1 , further comprising the step of varying a deflection speed and/or a beam power of said high energy beam when the already fused thickness below said powder which is to be fused is less than a predetermined thickness.

7. A method for altering a spot size of a high energy beam in an additive manufacturing apparatus for forming a three-dimensional article through successive fusion of parts of at least one layer of powder provided on a work table, which parts correspond to successive cross sections of the three-dimensional article, said method comprising the steps of:
providing a deflection source for deflecting the high energy beam on said powder material to provide a protracted beam spot movable over an intended scanning path in a scanning direction used for fusing said powder material;
varying a Full Width Half Maximum (FWHM) of said high energy beam only if an already fused thickness of said three-dimensional article below said layer of powder which is to be fused is less than a predetermined thickness; and
wherein a mean spot size of the protracted beam spot in a direction perpendicular to the scanning direction is smaller than a mean spot size of the protracted beam spot in a direction parallel to the scanning direction for a full scan length, a full cross section, and/or for a full 3-dimensional article,
wherein said FWHM of said high energy beam is decreased for a decreased already fused thickness of said three dimensional article.

8. The method according to claim 7 , wherein said fusing step is performed by an element selected from the group consisting of: a focus lens, an astigmatism lens, a vacuum level, a grid potential of an electron beam source, or an aperture size of a laser beam source.

Assignees

• Arcam Ab

Inventors

• Elfstroem Isak
• Fager Mattias

Classifications

• Y02P10/25

  Process efficiency · CPC title

• B22F12/49

  Scanners · CPC title

• B22F12/45

  Two or more · CPC title

• B22F12/44

  characterised by the configuration of the radiation means · CPC title

• B22F10/385

  Overhang structures · CPC title