Additive manufacturing method and apparatus

Patent metadata

Field	Value
Publication number	US-2019054533-A1
Application number	US-201816169290-A
Country	US
Kind code	A1
Filing date	Oct 24, 2018
Priority date	Nov 1, 2012
Publication date	Feb 21, 2019
Grant date	—

Abstract

A method and apparatus for fabricating an object. The method and apparatus entail applying a pulsed laser energy to a first quantity of a powder material on a substrate so as to fuse particles of the powder material into a first layer on the substrate, and then forming at least one additional layer on the first layer by applying a pulsed laser energy to at least a second quantity of the powder material on the first layer so as to fuse particles of the powder material into the at least one additional layer on the first layer. The pulsed laser energy is applied in a controlled manner such that solidification dynamics of the first and second quantities of the powder material are altered to promote at least one microstructural characteristic of the first and additional layer.

First claim

What is claimed is:

1 . An additive manufacturing apparatus, comprising:
a pulsed-laser generating system; and a controller configured to:
apply a pulsed laser energy to a first quantity of a powder material on a substrate so as to fuse particles of the powder material into a first layer on the substrate;
form at least one additional layer on the first layer by applying a pulsed laser energy to at least a second quantity of the powder material on the first layer so as to fuse particles of the powder material into the at least one additional layer on the first layer; and
apply the pulsed laser energy in a controlled manner such that solidification dynamics of the first and second quantities of the powder material are altered to promote at least one microstructural characteristic of the object comprising the first layer and the at least one additional layer.

2 . The additive manufacturing apparatus of claim 1 , wherein the controlled manner of applying the pulsed laser energy causes the first and second quantities of the powder material to fully melt.

3 . The additive manufacturing apparatus of claim 1 , wherein the controlled manner of applying the pulsed laser energy reduces at least one microstructural defect in the first layer and the at least one additional layer, and the at least one microstructural defect is chosen from the group consisting of microcracks and porosity.

4 . The additive manufacturing apparatus of claim 1 , wherein the powder material is a metallic powder material.

5 . The additive manufacturing apparatus of claim 4 , wherein the metallic powder material is a metal material prone to microcracking resulting from rapid solidification and localized heating.

6 . The additive manufacturing apparatus of claim 1 , wherein the controlled manner of applying the pulsed laser energy causes the pulsed laser energy to have a global energy density that causes the object to be free of microcracks and porosity, wherein the global energy density is calculated with the equation:
Global Energy Density= P avg /vs,
where P avg is laser peak power multiplied by duty cycle, v is scan velocity, and s is hatch spacing.

Assignees

• Gen Electric

Inventors

• Kenney Patrick Michael
• Lindley Dustin Eugene

Classifications

• B22F10/366

  Scanning parameters, e.g. hatch distance or scanning strategy · CPC title

• B22F12/43

  pulsed; frequency modulated · CPC title

• B22F12/41

  characterised by the type, e.g. laser or electron beam · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y50/00

  Data acquisition or data processing for additive manufacturing · CPC title