Patent EP0166676A2 successfully refreshed from Google Patents.
EP0166676A2
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EP
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Abrasive surfaced article for high temperature service
Assignee: RTX Corp
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Filing: 1985-06-20
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Granted: —
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Expires: 2005-06-20
Abstract
Abstract A very thin abrasive material (26) on a substrate (24, 28) is comprised of ceramic particulates (30) contained within a metal matrix (36). The particulates extend fully through the matrix from the substrate surface (32) to the machined free surface (44) of the abrasive. In a representative 0.38 mm abrasive the particulates are sized nominally at 0.42-0.50 mm and have an aspect ratio of less than 1.9 to 1. This enables a high density of particulates, in the range 33-62 per cm 2 , while at the same time ensuring good bonding in that most of the particulates are fully surrounded by matrix. When the abrasive is applied to the tip of a superalloy gas turbine engine blade (20), about 10-50% of the matrix metal is removed after machining. This allows the machined ceramic particulates (30) to project into space and to thus better interact with ceramic abradable seals. In the preferred practice of the invention the particulates are alumina coated silicon carbide contained in a nickel superalloy matrix.
Inventors
- 👤 Alfred Pio Matarese
- 👤 Richard Charles Novak
- 👤 Harry Edwin Eaton
- 👤 James Michael Goodman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 18:19
CPC Classifications
B; B24; B24D; B24D3/00; F; F01; F01D; F01D11/00; F01D11/08; F01D11/12; C; C23; C23C; C23C4/00; C23C4/18
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
45 words
An article comprised of a substrate to the surface of which is adhered an abrasive material comprised of metal matrix and ceramic particulates, the preponderance of the ceramic particulates extending through the matrix from the substrate surface to a machined surface of the abrasive material.
Claim 2
Dependent Claim
45 words
An article comprised of a substrate to the surface of which is adhered an abrasive material comprised of metal matrix and ceramic particulates, the preponderance of the ceramic particulates extending through the matrix from the substrate surface to a machined surface of the abrasive material.
Claim 3
Dependent Claim
58 words
An article shaped as a turbine engine airfoil having a curved tip surface to which is adhered an abrasive material comprised of a metal matrix surrounding ceramic particulates; the preponderance of the particulates lying in a single layer, contacting the tip surface and extending with essentially equal lengths through the matrix to a free surface of the abrasive.
Claim 4
Dependent Claim
58 words
An article shaped as a turbine engine airfoil having a curved tip surface to which is adhered an abrasive material comprised of a metal matrix surrounding ceramic particulates; the preponderance of the particulates lying in a single layer, contacting the tip surface and extending with essentially equal lengths through the matrix to a free surface of the abrasive.
Claim 5
Dependent Claim
78 words
An article made of superalloy and shaped as a turbine engine airfoil having a curved tip surface to which is adhered an abrasive material comprised of a high temperature alloy metal matrix surrounding ceramic particulates; the preponderance of the particulates lying in a single layer, contacting the tip surface and extending with essentially equal lengths through the matrix to a free surface of the abrasive, the particulates characterized by an aspect ratio of less than 1.9 to 1.
Claim 6
Dependent Claim
78 words
An article made of superalloy and shaped as a turbine engine airfoil having a curved tip surface to which is adhered an abrasive material comprised of a high temperature alloy metal matrix surrounding ceramic particulates; the preponderance of the particulates lying in a single layer, contacting the tip surface and extending with essentially equal lengths through the matrix to a free surface of the abrasive, the particulates characterized by an aspect ratio of less than 1.9 to 1.
Claim 7
Dependent Claim
26 words
The article of claim 1, 2 or 3 characterized by the abrasive material having particulates substantially regularly spaced at 33-62 particulates per cm of article surface.
Claim 8
Dependent Claim
14 words
The article of claim 4 having at least 42 particulates per cm 2 .
Claim 9
Dependent Claim
26 words
The article of claim 1, 2 or 3 characterized by ceramic particulates surrounded by a thin metal cladding interdiffused with a matrix metal of different composition.
Claim 10
Dependent Claim
24 words
The article of claim 1, 2 or 3 characterized by ceramic particulates which are sized between No. 20 and No. 40 U.S. Sieve Series.
Claim 11
Dependent Claim
17 words
The article of claim 6 characterized by less than 15 percent of the particulates contacting one another.
Claim 12
Dependent Claim
33 words
The article of claim 1, 2 or 3 wherein the free or machined surface of the abrasive material is characterized by machined ceramic particulates protruding partially from the matrix in essentially even amounts.
Claim 13
Dependent Claim
16 words
The article of claim 9 wherein 10-50 percent of a typical particulate protrudes from the matrix.
Claim 14
Dependent Claim
37 words
The article of claim 6 characterized by a matrix which is an oxidation resistant Fe, Co or Ni base alloy containing Cr and A1, wherein the matrix adjacent each particulate is relatively depleted in Cr or Al.
Claim 15
Dependent Claim
19 words
The article of claim 1, 2 or 3 characterized by a plasma sprayed superalloy matrix and silicon carbide particulates.
Claim 16
Dependent Claim
37 words
The article of claim 12 characterized by an abrasive material which by volume percent is made to be 10-20 silicon carbide, balance matrix, as measured when the matrix and particulates have the same thickness on a surface.
Claim 17
Independent Claim
133 words
The method of providing an abrasive material comprised of particulates and matrix on the surface of an article characterized by adhering a single layer of spaced apart ceramic particulates having a metal cladding to the article surface; causing the metal cladding to adhere to the surface so that the particulates are thereby adhered to the article and project from the surface in spaced apart fashion; depositing on the surface a lzyer of metal to fill the spaces between the particulates with matrix material which inherently has voids; heating the article to an elevated temperature to densify the matrix and to metallurgically bond the matrix to the metal clad particulates and the substrate; and machining the surface on the abrasive material to a finish surface so that the particulates are visible at the surface.
Claim 18
Independent Claim
133 words
The method of providing an abrasive material comprised of particulates and matrix on the surface of an article characterized by adhering a single layer of spaced apart ceramic particulates having a metal cladding to the article surface; causing the metal cladding to adhere to the surface so that the particulates are thereby adhered to the article and project from the surface in spaced apart fashion; depositing on the surface a lzyer of metal to fill the spaces between the particulates with matrix material which inherently has voids; heating the article to an elevated temperature to densify the matrix and to metallurgically bond the matrix to the metal clad particulates and the substrate; and machining the surface on the abrasive material to a finish surface so that the particulates are visible at the surface.
Claim 19
Dependent Claim
17 words
The method of claim 14, characterized by depositing the layer of metal using a line-of-sight deposition process.
Claim 20
Dependent Claim
13 words
The method of claim 15 characterized by using plasma arc spraying for depositing.
Claim 21
Dependent Claim
28 words
The method of claim 14, characterized by sizing the ceramic particulates to predominately have a nominal dimension greater than the thickness to which the abrasive material is machined.
Claim 22
Dependent Claim
39 words
The method of claim 17, characterized by using argon gas hot isostatic pressing to generate a temperature of at least 1065°C and a pressure of at least 130 MPa, to which pressure said matrix is essentially impenetrable when deposited.
Claim 23
Dependent Claim
34 words
The-method of claim 14 characterized by adhering particulates which are sized between No. 20 and 40 U.S. Sieve Series to the surface with a density of 33-62 particulates per cm 2 of substrate surface.
Claim 24
Dependent Claim
30 words
The method of claim 14 characterized by sizing and spacing the particulates so that less than 15 percent are contacting one another when they are metallically adhered on the surface.
Claim 25
Dependent Claim
43 words
The method of claim 14 characterized by removing a portion of the matrix layer after machining of the abrasive to decrease its thickness and to thereby free the portions of the particulates which extend to the machined abrasive material surface of surrounding matrix.
Claim 26
Dependent Claim
16 words
The method of claim 14 characterized in that 10-50 percent of the matrix thickness is removed.
Claim 27
Dependent Claim
41 words
The method of claim 14 characterized by bonding the metal clad ceramic particulate to the substrate surface with an organic adhesive to position it prior to metallically adhering it to the surface, and then removing the adhesive during the adhering step.
Claim 28
Dependent Claim
42 words
The method of claim 14 characterized in that the article is a gas turbine superalloy blade and the abrasive material is formed on a curved tip surface, characterized by machining the abrasive material surface so the abrasive material has a uniform thickness.
Claim 29
Dependent Claim
33 words
The method of claim 14, characterized in that the metallic adhering is achieved by sintering at an elevated temperature in an inert atmosphere which avoids oxidation of the metal which clads the particulate.
Claim 30
Dependent Claim
19 words
The method of claim 14 characterized by depositing particulates having an aspect ratio of less than 1.9 to 1.
Claim 31
Dependent Claim
19 words
The method of claim 23, characterized by particulates having an aspect ratio of about 1.5 to 1 or less.
Claim 32
Dependent Claim
50 words
The method of claim 16 characterized by heating the article surface to at least 700°C before and during plasma arc spraying at a subatmospheric pressure, to form an impermeable matrix layer; and then, hot isostatic pressing the matrix layer to densify and bond the layer to the particulate and substrate.
References Cited (Backward Citations)
No citation records indexed.
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