Molded articles

Patent metadata

Field	Value
Publication number	US-9475119-B2
Application number	US-201213566609-A
Country	US
Kind code	B2
Filing date	Aug 3, 2012
Priority date	Aug 3, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A method comprising introducing a first casting material into a casting mold; applying directional solidification to the first casting material in the casting mold; introducing a second casting material into the casting mold, the second casting material having a different chemical composition than the first casting material; applying directional solidification to the second casting material in the casting mold; and forming a molded article, wherein the molded article comprises a first region.

First claim

The invention claimed is:

1. A molded article comprising:
a first region formed by a first casting material; and
a second region formed by mixing a molten or liquid portion of the first casting material and a second casting material,
wherein the first casting material has a different chemical composition than the second casting material,
wherein the first region and the second region are cast as one integral casting using directional solidification, and
wherein the second region exhibits reduced thermal cracking relative to the first region.

2. The molded article of claim 1 , wherein the molded article has a lower concentration of impurities than were present in the first casting material and the second casting material.

3. The molded article of claim 1 , wherein the first region and the second region have different microstructure patterns.

4. The molded article of claim 1 , wherein the second region further exhibits reduced material loss relative to the first region.

5. The molded article of claim 1 , wherein thermal cracking is reduced by about 5% to about 80% in the second region relative to the first region using the same testing conditions.

6. A molded turbine bucket for use in a gas turbine engine, the turbine bucket comprising:
a hub; and
a blade, the blade including
a first region formed by a first casting material, and
a second region formed by mixing a molten or liquid portion of the first casting material and a second casting material,
wherein the first casting material has a different chemical composition than the second casting material and the first region and the second region are cast as one integral casting using directional solidification,
wherein the second region exhibits reduced thermal cracking relative to the first region, and
wherein the second region corresponds to a tip portion of the blade and the first region corresponds to the remaining balance of the blade.

7. The turbine bucket of claim 6 , wherein the turbine bucket has a lower concentration of impurities than were initially present in the first casting material and the second casting material when they each were introduced into a casting mold to mold the turbine bucket.

8. The turbine bucket of claim 6 , wherein the turbine bucket is a stage 1 turbine bucket and the tip portion of the blade is a squealer tip.

9. The turbine bucket of claim 6 , wherein the turbine bucket is a latter stage turbine bucket, and wherein the tip portion of the blade is a tip shroud.

10. The turbine bucket of claim 9 , wherein the second region provides targeted reinforcement to prevent or significantly reduce creep damage in the tip shroud.

Assignees

• Cui Yan
• Bucci David Vincent
• Feng Ganjiang
• Kottilingam Srikanth Chandrudu
• Lin Dechao
• Gen Electric

Inventors

• Cui Yan
• Bucci David Vincent
• Feng Ganjiang
• Kottilingam Srikanth Chandrudu
• Lin Dechao

Classifications

• B32B15/04

  comprising metal as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a bituminous or tarry layer B32B11/08; next to a water-setting substance layer B32B13/06; next to a glass layer B32B17/061; next to a cellulosic plastic layer B32B23/042)} · CPC title

• B32B15/20

  comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} · CPC title

• B22D27/045 Primary

  Directionally solidified castings · CPC title

• C30B28/06

  by normal freezing or freezing under temperature gradient · CPC title

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title