Effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys.
Saved in:
| Title: | Effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys. |
|---|---|
| Authors: | Itoh, Y.1, Saitoh, M.1, Takaki, K.1, Fujiyama, K.1 |
| Source: | Fatigue & Fracture of Engineering Materials & Structures. Dec2001, Vol. 24 Issue 12, p843-854. 12p. 5 Black and White Photographs, 1 Diagram, 2 Charts, 6 Graphs. |
| Subjects: | Protective coatings, Metal fatigue, Heat resistant alloys |
| Abstract: | This study concerns MCrAlY coatings (M is Ni, Co or both) sprayed by a vacuum plasma spraying process for protection against high-temperature corrosion and oxidation of gas turbine components, such as turbine blades and duct segments. The effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys were investigated at high temperature under push–pull loading and rotary bending and then compared with uncoated superalloys, such as equiaxed IN738LC, unidirectional solidified CM247LC and single-crystal CMSX-2. The high-cycle fatigue lives of MCrAlY-coated superalloys at high temperature under push–pull loading showed an inferior performance when compared with the uncoated superalloys. This was because the crack initiation site was different. The high-cycle fatigue cracks of nickel-based superalloys initiated at casting cavities which were exposed on the specimen surface, whereas the high-cycle fatigue cracks of MCrAlY-coated specimens initiated at interface defects, such as small pores and grid residue, between the MCrAlY coating and the substrate and grew into the MCrAlY coating, and then into the substrate. Similarly, the rotary bending fatigue properties of MCrAlY-coated superalloys at high temperature showed an inferior performance when compared with the uncoated superalloys. This is because of a high stress due to the higher Young’s modulus of the MCrAlY coating (in comparison with the substrate) being induced at the MCrAlY coating surface. The crack initiation site was on the specimen surface in both cases of the nickel-based superalloys and the MCrAlY-coated superalloys, respectively. As a result, it was considered that, for rotary bending tests, the fatigue life reduction was due to the high stress that originated from the difference of elastic constants between the MCrAlY coating and the superalloy. Consequently, in fatigue life design it is necessary to take account of the stress levels in a coating layer. [ABSTRACT FROM AUTHOR] |
| Copyright of Fatigue & Fracture of Engineering Materials & Structures is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Links: – Type: pdflink Text: Availability: 0 |
|---|---|
| Header | DbId: egs DbLabel: Engineering Source An: 5712192 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: Effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Itoh%2C+Y%2E%22">Itoh, Y.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Saitoh%2C+M%2E%22">Saitoh, M.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Takaki%2C+K%2E%22">Takaki, K.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Fujiyama%2C+K%2E%22">Fujiyama, K.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Fatigue+%26+Fracture+of+Engineering+Materials+%26+Structures%22">Fatigue & Fracture of Engineering Materials & Structures</searchLink>. Dec2001, Vol. 24 Issue 12, p843-854. 12p. 5 Black and White Photographs, 1 Diagram, 2 Charts, 6 Graphs. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Protective+coatings%22">Protective coatings</searchLink><br /><searchLink fieldCode="DE" term="%22Metal+fatigue%22">Metal fatigue</searchLink><br /><searchLink fieldCode="DE" term="%22Heat+resistant+alloys%22">Heat resistant alloys</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: This study concerns MCrAlY coatings (M is Ni, Co or both) sprayed by a vacuum plasma spraying process for protection against high-temperature corrosion and oxidation of gas turbine components, such as turbine blades and duct segments. The effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys were investigated at high temperature under push–pull loading and rotary bending and then compared with uncoated superalloys, such as equiaxed IN738LC, unidirectional solidified CM247LC and single-crystal CMSX-2. The high-cycle fatigue lives of MCrAlY-coated superalloys at high temperature under push–pull loading showed an inferior performance when compared with the uncoated superalloys. This was because the crack initiation site was different. The high-cycle fatigue cracks of nickel-based superalloys initiated at casting cavities which were exposed on the specimen surface, whereas the high-cycle fatigue cracks of MCrAlY-coated specimens initiated at interface defects, such as small pores and grid residue, between the MCrAlY coating and the substrate and grew into the MCrAlY coating, and then into the substrate. Similarly, the rotary bending fatigue properties of MCrAlY-coated superalloys at high temperature showed an inferior performance when compared with the uncoated superalloys. This is because of a high stress due to the higher Young’s modulus of the MCrAlY coating (in comparison with the substrate) being induced at the MCrAlY coating surface. The crack initiation site was on the specimen surface in both cases of the nickel-based superalloys and the MCrAlY-coated superalloys, respectively. As a result, it was considered that, for rotary bending tests, the fatigue life reduction was due to the high stress that originated from the difference of elastic constants between the MCrAlY coating and the superalloy. Consequently, in fatigue life design it is necessary to take account of the stress levels in a coating layer. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Fatigue & Fracture of Engineering Materials & Structures is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=5712192 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1046/j.1460-2695.2001.00453.x Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 12 StartPage: 843 Subjects: – SubjectFull: Protective coatings Type: general – SubjectFull: Metal fatigue Type: general – SubjectFull: Heat resistant alloys Type: general Titles: – TitleFull: Effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Itoh, Y. – PersonEntity: Name: NameFull: Saitoh, M. – PersonEntity: Name: NameFull: Takaki, K. – PersonEntity: Name: NameFull: Fujiyama, K. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 12 Text: Dec2001 Type: published Y: 2001 Identifiers: – Type: issn-print Value: 8756758X Numbering: – Type: volume Value: 24 – Type: issue Value: 12 Titles: – TitleFull: Fatigue & Fracture of Engineering Materials & Structures Type: main |
| ResultId | 1 |
