Casting mold, method of manufacturing same, TiAl alloy cast product, and method of casting same

Patent metadata

Field	Value
Publication number	US-11014143-B2
Application number	US-201615273442-A
Country	US
Kind code	B2
Filing date	Sep 22, 2016
Priority date	Mar 28, 2014
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A casting mold to cast a TiAl alloy includes a casting mold body formed into a bottomed shape and provided with a cavity. The casting mold body includes a reaction-resistant layer provided on the cavity side, formed from a refractory material containing at least one of cerium oxide, yttrium oxide, and zirconium oxide and a back-up layer formed on the reaction-resistant layer. The back-up layer includes a weakening layer formed from a refractory material including a silica material in a range from 80% by mass to 100% by mass inclusive, the silica material containing cristobalite in a range from 26% by mass to 34% by mass inclusive and the rest being fused silica, the weakening layer being designed to reduce casting mold strength and a shape-retention layer formed from a refractory material.

First claim

What is claimed:

1. A casting mold to cast a TiAl alloy, comprising:
a casting mold body formed into a bottomed shape and provided with a cavity into which a molten TiAl alloy is to be poured, wherein
the casting mold body includes
a reaction-resistant layer provided on the cavity side, formed from a refractory material containing at least one of cerium oxide, yttrium oxide, and zirconium oxide, and configured to suppress a reaction with the molten TiAl alloy, and
a back-up layer formed on the reaction-resistant layer, and

the back-up layer includes
a weakening layer formed from a refractory material including a silica material in a range from 80% by mass to 100% by mass inclusive, the silica material containing cristobalite in a range from 26% by mass to 34% by mass inclusive and the rest being fused silica, the weakening layer being designed to reduce casting mold strength so that cracks occur on the casting mold in a cooling process from 1100° C. to 1000° C. after casting, and
a shape-retention layer formed from a refractory material and designed to retain a casting mold shape, and

the casting mold flexural strength at to 1100° C. is in a range from 3.8 MPa to 9.2 MPa inclusive.

2. The casting mold according to claim 1 , wherein the refractory material forming the weakening layer includes the silica material in a range from 90% by mass to 100% by mass inclusive.

3. The casting mold according to claim 1 , wherein the weakening layer is formed directly on the reaction-resistant layer.

4. The casting mold according to claim 1 , wherein the casting mold body includes:
a blade body casting portion to cast a blade body;
a shroud casting portion to cast a shroud; and
a platform casting portion to cast a platform.

5. The casting mold according to claim 2 , wherein the refractory material forming the weakening layer consists of the silica material.

Assignees

• Ihi Corp

Inventors

• Satoh Shigeyuki
• Sekiguchi Tatsuya

Classifications

• B22C3/00

  Selection of compositions for coating the surfaces of moulds, cores, or patterns · CPC title

• B22D25/02

  by its peculiarity of shape; of works of art {(cylinders, pistons B22D15/02)} · CPC title

• B22C9/04

  Use of lost patterns · CPC title

• F05D2300/174

  Titanium alloys, e.g. TiAl · CPC title

• B22C9/12

  Treating moulds or cores, e.g. drying, hardening · CPC title