Forming method of thermal insulation film

Patent metadata

Field	Value
Publication number	US-9702052-B2
Application number	US-201514933599-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 7, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A forming method of a thermal insulation film, including: a first step of forming an anode oxidation coating film on an aluminum-based wall surface, the anode oxidation coating film including micro-pores each having a diameter of micrometer-scale and nano-pores each having a diameter of nanometer-scale; a second step of abrading a surface of the anode oxidation coating film with abrasive powders and bringing the abrasive powders into the micro-pores located at the formed abraded surface; and a third step of forming a protection film on the abraded surface to produce a thermal insulation film including the anode oxidation coating film and the protection film.

First claim

What is claimed is:

1. A forming method of a thermal insulation film, comprising:
a first step of forming an anode oxidation coating film on an aluminum-based wall surface, the anode oxidation coating film including micro-pores each having a diameter of micrometer-scale and nano-pores each having a diameter of nanometer-scale;
a second step of abrading a surface of the anode oxidation coating film with abrasive powders to a prescribed depth to form an abraded surface and bringing the abrasive powders into the micro-pores located at the abraded surface; and
a third step of forming a protection film on the abraded surface to produce a thermal insulation film including the anode oxidation coating film and the protection film,
wherein the abrading reduces a thickness of the anode oxidation coating film in a direction from the surface of the anode oxidation coating film toward the aluminum-based wall surface.

2. The forming method of a thermal insulation film according to claim 1 , wherein the micro-pores at the abraded surface formed in the second step have a depth in a range from 1 to 10 μm, and the abrasive powders have an average particle size in a range below 1 μm.

3. The forming method of a thermal insulation film according to claim 2 , wherein the average particle size of the abrasive powders is above 100 nm.

4. The forming method of a thermal insulation film according to claim 1 , wherein in the third step, a polymer containing Si is coated on the abraded surface, and is fired to be converted into silicon dioxide, so as to form the protection film.

5. The forming method of a thermal insulation film according to claim 1 , wherein the abrasive powders brought into the micro-pores are adhered to each other by the protection film.

6. The forming method of a thermal insulation film according to claim 1 , wherein the aluminum-based wall surface is a wall surface of a combustion chamber of an internal combustion engine.

7. The forming method of a thermal insulation film according to claim 1 , wherein the reduction of the thickness is in the order of micrometers.

Assignees

• Toyota Motor Co Ltd
• Toyota Chuo Kenkyusho Kk

Inventors

• Nishikawa Naoki
• Tani Masaaki
• Hohjo Hiroshi

Classifications

• C25D11/246

  for sealing layers · CPC title

• C25D11/18 Primary

  After-treatment, e.g. pore-sealing · CPC title

• C25D11/04

  of aluminium or alloys based thereon · CPC title