ADDITIVE MANUFACTURING SYSTEM FOR MINIMIZING THERMAL STRESSES

• US 20150314373A1
• Filed: 04/17/2015
• Published: 11/05/2015
• Est. Priority Date: 05/01/2014
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Mironets, Sergey, Staroselsky, Alexander
• Granted Patent: US 10,556,270 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B22F 10/12 by photopolymerisation, e.g. stereolithography [SLA] or digital light processing [DLP]
• CPC Class Codes: B22F 10/25 Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS]
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 12/30 Platforms or substrates
• CPC Class Codes: B22F 12/67 Blades
• CPC Class Codes: B22F 2202/01 Use of vibrations
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/003 Apparatus, e.g. furnaces in general F27B
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A build plate for an additive manufacturing system is disclosed. The build plate includes a support structure, a sub-plate, and one or more transducers. The support structure is configured to support a stack of sintered layers of a pulverant material. Further, the support structure extends orthogonally to a build direction. The sub-plate is arranged along the support structure, and defines a transducer cavity. One or more transducers are arranged in the transducer cavities. The one or more transducers are operable to cause vibration of the support structure and the stack parallel to the build direction. Such vibration relieves internal stresses caused by sintering of the stack.

Claims

1. A build plate for an additive manufacturing system, the build plate comprising:

a support structure configured to support a stack of sintered layers of a pulverant material, the support structure extending orthogonally to a build direction;

a sub-plate arranged along the support structure, the sub-plate defining a transducer cavity;

one or more transducers arranged in the transducer cavity, wherein the one or more transducers are operable to cause vibration of the support structure and the stack parallel to the build direction, and wherein vibration relieves internal stresses caused by sintering of the stack.

2. The build plate of claim 1, wherein the one or more transducers are arranged throughout the sub-plate in a pattern corresponding to the shape of the stack.

3. The build plate of claim 1, wherein the one or more transducers include a pin oriented in the build direction.

4. The build plate of claim 1, wherein the build plate is coupled to a platform that is movable parallel to the build direction.

5. The build plate of claim 1, wherein the one or more transducers are operable in the ultrasonic frequency range.

6. The build plate of claim 1, wherein:

the one or more transducers are each operable within a range of frequencies, and/or;

the one or more transducers are each operable within a range of amplitudes.

7. The build plate of claim 6, wherein an operating frequency and/or an operating amplitude of the one or more transducers are selected based on the shape of the stack.

8. An additive manufacturing system comprising:

a pulverant material supply system configured to provide a pulverant material to a working surface;

a movable platform movable parallel to a build direction;

a build plate movable arranged on the movable platform, the build plate being movable from the working surface along with the movable platform, the build plate including one or more transducers operable to cause vibration of the build plate parallel to the build direction; and

a radiation system configured to provide a radiation beam to selectively sinter the pulverant material at the working surface to form a stack of sintered layers.

9. The additive manufacturing system of claim 8, wherein the one or more transducers are arranged throughout the build plate in a pattern corresponding to the shape of the stack.

10. The additive manufacturing system of claim 8, wherein the one or more transducers include a pin oriented in the build direction.

11. The additive manufacturing system of claim 8, wherein the one or more transducers are operable in the ultrasonic frequency range.

12. The additive manufacturing system of claim 8, wherein:

the one or more transducers are each operable within a range of frequencies, and/or;

the one or more transducers are each operable within a range of amplitudes.

13. The additive manufacturing system of claim 12, wherein an operating frequency and/or an operating amplitude of the one or more transducers is selected based on the shape of the stack.

14. The additive manufacturing system of claim 8, wherein the pulverant material supply system includes a recoater blade.

15. The additive manufacturing system of claim 8, wherein the radiation source is a laser.

16. The additive manufacturing system of claim 8, wherein:

the stack of layers of sintered pulverant material is arranged between the build plate and the working surface; and

one or more retractable transducers are coupled to the stack of layers of sintered pulverant material.

17. The additive manufacturing system of claim 16, wherein the one or more retractable transducers are operable to cause vibration of the stack.

18. A method of additively manufacturing a part, the method comprising:

arranging a build plate at a working surface;

positioning a pulverant material on the build plate;

selectively sintering a first layer of the pulverant material with a radiation beam;

moving the build plate away from the working surface, opposite a build direction;

selectively sintering additional layers of the pulverant material to form a stack; and

applying ultrasonic vibration to the stack during at least some of the steps of additive manufacturing.

19. The method of claim 18, wherein applying ultrasonic vibration to the stack comprises operating a transducer that is mechanically connected to the build plate.

20. The method of claim 18, wherein applying ultrasonic vibration to the stack further comprises operating a retractable transducer that is mechanically connected to the stack and arranged between the build plate and the working surface.