Post-processing of an object obtained by direct metal laser sintering

Patent metadata

Field	Value
Publication number	US-2023321727-A1
Application number	US-202118023871-A
Country	US
Kind code	A1
Filing date	Aug 25, 2021
Priority date	Sep 1, 2020
Publication date	Oct 12, 2023
Grant date	—

Abstract

The present invention relates to a method and a system for treating a surface of an object obtained by direct metal laser sintering. The object is sintered from a metal powder with a grain size distribution. Due to the manufacturing process, the object can comprise a rough surface with remaining grains of the metal powder attached to the surface. The method according to the present invention provides parameters for post-processing the object to achieve a smooth surface suitable for use in medical imaging systems.

First claim

1 . A method of treating a surface of an object, the method comprising:
providing the object obtained by direct metal laser sintering from a metal powder, the object having a maximum grain size of the metal powder and an initial surface roughness range; post-processing the surface of the object with a surface optimization technology, the surface optimization technology reducing a surface roughness of the surface of the object; measuring a post-processing surface roughness range of the surface; determining whether a condition of the post-processing surface roughness range is met, wherein the condition at least requires the post-processing surface roughness range being smaller than the initial surface roughness range by a factor of at least two, and the post-processing surface roughness range being smaller than the maximum grain size; and stopping treating the surface of the object when the condition is met, and repeating treating the surface of the object starting with post-processing the surface of the object when the condition is not met; wherein post-processing the surface of the object with the surface optimization technology comprises removing grains attached to the surface of the object.

2 . The method according to claim 1 , wherein the condition further requires the post-processing surface roughness range being smaller than the maximum grain size by a factor of at least two.

3 . The method according to claim 1 , wherein a surface roughness range is defined by a difference in elevation of a highest point of the surface of the object and a lowest point of the surface of the object.

4 . The method according to claim 1 , wherein the surface optimization technology is at least one of: sand blasting, electro polishing, laser polishing, chemical etching, thermal treatment, high-pressure treatment, and high-pressure treatment using a gas- and/or liquid substance comprising an additional abrasive material.

5 . The method according to claim 1 , wherein the object obtained by direct metal laser sintering is made of tungsten or molybdenum.

6 . The method according to claim 1 , wherein the object is an X-ray anti-scatter grid.

7 . The method according to claim 6 , wherein the X-ray anti-scatter grid comprises an array of channels, and wherein the initial surface roughness range and/or the post-processing surface roughness range are measured on an interior surface of a channel.

8 . The method according to claim 1 , wherein the initial surface roughness range and/or the post-processing surface roughness range is determined by scanning electron microscopy.

9 . The method according to claim 1 , wherein the maximum grain size is about 40 μm, and the post-processed surface roughness range is smaller than about 20 μm.

10 . (canceled)

11 . (canceled)

12 . A system for treating a surface of an object obtained by direct metal laser sintering from a metal powder, the system comprising:
a surface optimization unit configured for reducing a surface roughness of the surface of the object; a measurement unit configured for measuring a post-processing surface roughness range of the surface of the object; and a determination unit configured for determining whether a condition of the post-processing surface roughness range is met, wherein the condition comprises the post-processing surface roughness range being smaller than an initial surface roughness range by a factor of at least two, and the post-processing surface roughness range being smaller than a maximum grain size of the metal powder of the direct metal laser sintering, wherein post-processing the surface of the object with the surface optimization technology comprises removing grains attached to the surface of the object.

13 . A non-transitory computer-readable medium for storing executable instructions, which cause a method to be performed for treating a surface of an object, the method comprising:
post-processing the surface of the object with a surface optimization technology, the surface optimization technology reducing a surface roughness of the surface of the object, wherein the object is obtained by direct metal laser sintering from a metal powder, the object having a maximum grain size of the metal powder and an initial surface roughness range; measuring a post-processing surface roughness range of the surface; determining whether a condition of the post-processing surface roughness range is met, wherein the condition at least requires the post-processing surface roughness range being smaller than the initial surface roughness range by a factor of at least two, and the post-processing surface roughness range being smaller than the maximum grain size; and stopping the method of treating the surface of the object when the condition is met, and repeating treating the surface of the object starting with post-processing the surface of the object when the condition is not met, wherein post-processing the surface of the object with the surface optimization technology comprises removing grains attached to the surface of the object.

14 . (canceled)

Assignees

• Koninklijke Philips Nv

Inventors

• Vogtmeier Gereon
• Kok Christiaan

Classifications

• B22F10/28 Primary

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

• B22F10/68

  Cleaning or washing · CPC title

• B22F2203/00

  Controlling · CPC title

• B33Y50/00

  Data acquisition or data processing for additive manufacturing · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title