Operating a sintering furnace

Patent metadata

Field	Value
Publication number	US-2021121954-A1
Application number	US-201817058585-A
Country	US
Kind code	A1
Filing date	Nov 26, 2018
Priority date	Nov 26, 2018
Publication date	Apr 29, 2021
Grant date	—

Abstract

In an example implementation, a method of operating a sintering furnace includes receiving information about a green object load to be sintered in a sintering furnace, determining a sintering profile based on the information, and performing a sintering process according to the sintering profile. During the sintering process, a sensor reading that indicates a degree of densification of a green object in the load is accessed from a densification sensor. The method includes initiating a cool down phase of the sintering process if the sensor reading has reached a target sensor reading.

First claim

What is claimed is:

1 . A method of operating a sintering furnace comprising:
receiving information about a green object load to be sintered in a sintering furnace; determining a sintering profile based on the information; performing a sintering process according to the sintering profile; during the sintering process, accessing a sensor reading from a densification sensor that indicates a degree of densification of a green object in the load; and, initiating a cool down phase of the sintering process if the sensor reading has reached a target sensor reading.

2 . A method as in claim 1 , wherein performing a sintering process according to the sintering profile comprises:
increasing a sintering furnace temperature to a binder burnout temperature specified in the sintering profile; maintaining the binder burnout temperature for a burnout time specified in the sintering profile; and, increasing the sintering furnace temperature to a sintering temperature after the burnout time has elapsed.

3 . A method as in claim 2 , further comprising:
when the sensor reading has not reached the target sensor reading, accessing a maximum sintering time from the sintering profile; and, initiating the cool down phase if the sintering furnace temperature has been at the sintering temperature for a time that exceeds the maximum sintering time.

4 . A method as in claim 2 , comprising accessing the sensor reading after the sintering furnace temperature has reached the sintering temperature.

5 . A method as in claim 2 , further comprising:
as the sintering furnace temperature increases from the binder burnout temperature to the sintering temperature, accessing a pre-sintering sensor reading from the densification sensor to establish a pre-sintering sensory baseline.

6 . A method as in claim 1 , further comprising:
prior to performing the sintering process, accessing a pre-process sensor reading from the densification sensor; comparing the pre-process sensor reading with a pre-process sensor reference; and, providing a user notification if the pre-process sensor reading is outside of an acceptable range of the pre-process sensor reference.

7 . A method as in claim 1 , wherein receiving information about the green object load comprises receiving information selected from a total mass of green objects in the load, a thickness of side walls of the green objects in the load, a type of material forming the green objects in the load, and an amount and type of binder binding the material together in the green objects in the load.

8 . A method as in claim 1 , wherein determining a sintering profile comprises:
determining a maximum sintering time; determining a binder burnout temperature; determining a burnout time; and, determining a sintering temperature.

9 . A sintering system for operating a sintering furnace, comprising:
a sintering furnace to sinter a load of green objects; a densification sensor to provide a sensor reading that indicates a degree of densification of a token green object being sintered in the sintering furnace; and, a controller to compare the sensor reading with a target sensor value and to initiate a furnace cool down phase when the sensor reading reaches the target sensor value.

10 . A sintering system as in claim 9 , wherein the densification sensor comprises a sensor selected from an optical sensor, an electrical sensor, and a gas sensor.

11 . A sintering system as in claim 9 , wherein the densification sensor location is selected from a location outside of the sintering furnace, a location inside of the sintering furnace, and a location both outside and inside the sintering furnace.

12 . A method of operating a sintering furnace comprising:
during a sintering process to sinter green objects in a sintering furnace, and after the sintering furnace has reached a sintering temperature, accessing sensor data from a densification sensor that indicates a degree of densification of a token green object; starting a furnace cool down phase if the sensor data has reached a preset target; and, if the sensor data has not reached a preset target, starting the furnace cool down phase if the sintering furnace has been at the sintering temperature for a time period that exceeds a maximum sintering time.

13 . A method as in claim 12 , further comprising:
if the sintering furnace has not been at the sintering temperature for a time period that exceeds the maximum sintering time, accessing updated sensor data from the densification sensor; and, starting the furnace cool down phase if the updated sensor data has reached the preset target.

14 . A method as in claim 12 , further comprising:
prior to the sintering process, receiving information about the green objects; and, based on the green object information, determining a process profile to control the sintering process.

15 . A method as in claim 12 , further comprising:
prior to the sintering process, taking a pre-process sensor reading; comparing the pre-process sensor reading with a sensor reference; determining that the pre-process sensor reading is not within an acceptable range of the sensor reference; and, providing a notification to check the location of the token green object in the furnace prior to proceeding with the sintering process.

Assignees

• Hewlett Packard Development Co

Inventors

• Champion David
• Seaver Richard
• Suri Pavan

Classifications

• Y02P10/25

  Process efficiency · CPC title

• B22F10/64

  by thermal means (control of energy beam parameters for post heating B22F10/364) · CPC title

• G01N9/00

  Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity · CPC title

• B22F3/10

  Sintering only · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title