Thermal isolation spray for casting articles

• US 10,434,568 B2
• Filed: 03/15/2013
• Issued: 10/08/2019
• Est. Priority Date: 04/12/2012
• Status: Active Grant

• Current Assignee: REL, Inc.
• Original Assignee: Loukus Technologies, Inc.
• Inventors: Loukus, Josh E., Loukus, Adam R., Pennala, Travis, Luskin, Luke
• Primary Examiner(s): Kerns, Kevin P
• Assistant Examiner(s): Ha, Steven S
• Application Number:
  US13/836,001
• Publication Number:
  US 20130269901A1
• Time in Patent Office: 2,398 Days
• Field of Search: 164 97, 164122, 164 91, 164120, 164271, 164284, 164312, 1563082, 428210
• CPC Class Codes: B22C 9/00 Moulds or cores uniquely adapted to particular casting processes B22D; Moulding processes
• CPC Class Codes: B22D 17/00 Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
• CPC Class Codes: B22D 17/2023 Nozzles or shot sleeves
• CPC Class Codes: B22D 17/203 Injection pistons B22D17/2053 takes precedence; for plastics B29C45/53
• CPC Class Codes: B22D 17/22 Dies manufacture, see the appropriate class, e.g. B23P15/24; Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies
• CPC Class Codes: B22D 19/0081 pretreatment of the insert, e.g. for enhancing the bonding between insert and surrounding cast metal
• CPC Class Codes: B22D 19/02 for making reinforced articles B22D19/14 takes precedence
• CPC Class Codes: B22D 19/08 for building-up linings or coverings, e.g. of anti-frictional metal
• CPC Class Codes: B22D 19/14 the objects being filamentary or particulate in form making alloys containing fibres or filaments by contacting the fibres or filaments with molten metal C22C47/08
• CPC Class Codes: B22D 27/04 Influencing the temperature of the metal, e.g. by heating or cooling the mould
• CPC Class Codes: C04B 14/46 Rock wool ; Ceramic or silicate fibres C04B14/40, C04B14/42 take precedence
• CPC Class Codes: C04B 2111/00525 for metallic surfaces
• CPC Class Codes: C04B 2111/00577 applied by spraying
• CPC Class Codes: C04B 30/02 containing fibrous materials
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer

Abstract

Embodiments provide methods, apparatuses and systems for depositing a thermal insulator coating onto a desired surface of a mold cavity or insert or preform. Embodiments also provide casting methods using a thermal insulator coating.

Claims

1. A method for casting an article, comprising:

spray-depositing a thermal insulator coating onto an inside surface of a mold cavity, the spray-depositing comprising spraying a fibrous coating mixture to a thickness of 0.01 to 0.2 inches onto the inside surface of the mold cavity and allowing the fibrous coating mixture to dry, the fibrous coating mixture consisting of ceramic fibers and a liquid and an optional release agent; and

introducing a molten material into the mold cavity and in contact with the thermal insulator coating, wherein the molten material within the mold cavity remains in a molten state for a predetermined dwell time.

2. The method of claim 1 wherein the predetermined dwell time extends from the introducing the molten material into the mold cavity at least until the molten material fills a specified portion of the mold cavity.

3. The method of claim 2 wherein the predetermined dwell time extends from the introducing the molten material into the mold cavity at least until the molten material fills substantially the entire mold cavity.

4. The method of claim 3 wherein the predetermined dwell time extends from the introducing the molten material into the mold cavity at least until a desired pressure is applied to the molten material.

5. The method of claim 1 further comprising positioning a preform or insert into the mold cavity.

6. The method of claim 5 wherein the preform or the insert has a previously spray-deposited coating of thermal insulating material.

7. The method of claim 6 wherein the preform or the insert has a cladding metal surrounding at least a portion of the previously spray-deposited coating of thermal insulating material.

8. The method of claim 1 wherein the thermal insulator coating is a first thermal insulator coating and the method further comprises spray-depositing a second thermal insulator coating over a surface of the molten material.

9. The method of claim 8 wherein the molten material is a first molten material and the method further comprises depositing a second molten material over a surface of the second thermal insulator coating.

10. The method of claim 9 wherein the method further comprises spray-depositing a third thermal insulator coating over a surface of the second molten material.

11. A method for casting an article, comprising:

spray-depositing a thermal insulator coating onto a surface of a preform or insert, the spray-depositing comprising spraying a fibrous coating mixture onto the surface of the preform or insert to a thickness of 0.01 to 0.2 inches and allowing the fibrous coating mixture to dry, the fibrous coating mixture consisting of ceramic fibers and a liquid and an optional release agent;

positioning the preform or insert into a mold cavity; and

introducing a molten material into the mold cavity and in contact with the thermal insulator coating, wherein the thermal insulator coating isolates the preform or insert from the molten material for a predetermined dwell time.

12. The method of claim 11 wherein the predetermined dwell time extends from the introducing the molten material into the mold cavity at least until the molten material fills a specified portion of the mold cavity.

13. The method of claim 12 wherein the predetermined dwell time extends from the introducing the molten material into the mold cavity at least until the molten material fills substantially the entire mold cavity.

14. The method of claim 13 wherein the predetermined dwell time extends from the introducing the molten material into the mold cavity at least until a desired pressure is applied to the molten material.

15. The method of claim 11 further comprising encapsulating at least a portion of the preform or the insert after the step of spray-depositing a thermal insulator coating onto a surface of a preform or insert and before the step of positioning the preform or insert into a mold cavity.

16. The method of claim 11 wherein the thermal insulator coating is a first thermal insulator coating and the method further comprises spray-depositing a second thermal insulator coating onto an inside surface of the mold cavity and introducing a molten material into the mold cavity and in contact with both the first thermal insulator coating and the second thermal insulator coating.

17. A method for casting an article, comprising:

identifying an inside surface x of a mold cavity and an inside surface y of the mold cavity, the surface x being a surface desiring to have a longer isolation time from molten material than the surface y;

spray-depositing a first thermal insulator coating onto the surface x to a thickness of 0.01 to 0.2 inches; and

spray-depositing a second thermal insulator coating onto the surface y, wherein the first thermal insulator coating is thicker than the second thermal insulator coating, and wherein spray-depositing the first thermal insulator coating and/or the second thermal insulator coating comprises spraying a fibrous coating mixture onto the surface x and/or the surface y and allowing the fibrous coating mixture to dry;

wherein the fibrous coating mixture consists of ceramic fibers and a liquid and an optional release agent.

18. A method for casting an article, comprising:

spray-depositing a thermal insulator coating onto a surface of a mold cavity; and

introducing a molten material into the mold cavity and in contact with the thermal insulator coating;

wherein the molten material within the mold cavity remains in a molten state for a predetermined dwell time;

wherein the thermal insulator coating is a first thermal insulator coating and the method further comprises spray-depositing a second thermal insulator coating over a surface of the molten material; and

wherein the molten material is a first molten material and the method further comprises depositing a second molten material over a surface of the second thermal insulator coating.

19. The method of claim 18 wherein the method further comprises spray-depositing a third thermal insulator coating over a surface of the second molten material.