Title of Invention	A FRICTION STIR SURFACING METHOD TO PRODUCE A COMPACTED SURFACE LAYER ON A SUBSTRATE USING A METALLIC POWDER MATERIAL
Abstract	An improved friction surfacing method to produce a surfaced layer on a substrate using powder material the method comprising: - providing a substrate having a base material (6); - providing a rotatable tool (1) having a profiled configuration (4) and a hole (2) to conduct a powder material therethrough; - rotating the tool (1) and moving the rotating tool (1) in a direction parallel to the substrate (6); - pressing the rotating tool (1) on the base material (6) and conducting a power material via the hole (2) in a direction towards the profiled configuration (4); wherein the friction pressure generating heat to transform the base and/or the power material to a plasticised condition which produces a compacted surface deposit (7) on the substrate.

Title of Invention

A FRICTION STIR SURFACING METHOD TO PRODUCE A COMPACTED SURFACE LAYER ON A SUBSTRATE USING A METALLIC POWDER MATERIAL

Abstract

An improved friction surfacing method to produce a surfaced layer on a substrate using powder material the method comprising: - providing a substrate having a base material (6); - providing a rotatable tool (1) having a profiled configuration (4) and a hole (2) to conduct a powder material therethrough; - rotating the tool (1) and moving the rotating tool (1) in a direction parallel to the substrate (6); - pressing the rotating tool (1) on the base material (6) and conducting a power material via the hole (2) in a direction towards the profiled configuration (4); wherein the friction pressure generating heat to transform the base and/or the power material to a plasticised condition which produces a compacted surface deposit (7) on the substrate.

Full Text	Field of Invention The present invention relates to weld surfacing of a material with similar / dissimilar material in the form of powders, using the heat generated by friction between surfaces in relative motion under pressure. More particularly, the present invention relates to an improved friction surfacing method including a tool to produce a surfaced layer on a substrate using powder material. Background of the invention Surfacing is a welding technique applied to industrial components operating in service conditions involving corrosive medium or various kinds of wear mechanisms or their combinations. Depending on the intensity and severity of the service environments, the operating surfaces are deposited with suitable materials to provide adequate service life to the component. The thickness of deposit depends upon the service, requirements. Weld surfacing is a technology widely used for the manufacture of new components including the repair and reclamation of serviced components. For the purpose, several types of welding and spraying techniques are employed. Several fusion welding techniques based on arc and/or gas flame are generally preferred due to the associated lower cost and ease of application. However, the arc welding techniques result in relatively thicker weld deposits and often require multi-layer deposits due to the higher level of dilution as consequent upon high- energy dissipation. This leads to higher consumption of welding consumables to achieve the required deposit surface properties. Spraying techniques are suitable for thinner surfaced layers. However while fusion welding produces strong metallurgical bonds, arc and gas based spraying techniques using powder material for creating the coated surface produce generally a mechanical bond 1 between the surfaced layer and the substrate. Hence, the surfaced layer may get disbonded with the impact loading. Patent No. EP0474455 discloses a process for surfacing of materials using frictional heat generated by moving surfaces in contact under pressure. The process involves the use of a rotating consumable in the form of a rod. The rod is pressed against the material to be surfaced raising the temperature of the rod material and / or the base metal to their plastic temperature. As the rotating tool moves in a linear direction, the plasticised material of the tool is transferred to the member being surfaced and forms a deposited layer. Patent No. U52005000424 describes a method for the formation of a deposit of special characteristics using high velocity hot gas and powder filler material. The powder particles heated to high temperature by the high velocity hot gas impinge on the surface of the material on which the deposit is being created. The impinging particles are mechanically locked on to the surface and between themselves, resulting on a surface deposited layer. All the prior art methods however entails defects like porosity in the weld deposit, material loss, lack of proper bonding, improper thickness and bead appearance. Further, such processes require costly and Intricate equipment. Objects of the Invention It is an object of the invention to propose an improved friction surfacing method to produce a surfaced layer on a substrate using powder material which eliminates the disadvantages of the prior art. 2 Another object of the invention is to propose an improved friction surfacing method to produce a surfaced layer on a substrate using powder material which makes use of powder fillers to produce thin layers of deposits. A further object of the invention is to propose an improved friction surfacing method to produce a surfaced layer on a substrate using powder material which is capable of producing a thin deposit with good bonding over a wider area on a substrate using multiple adjacent passes. A still further object of the invention is to propose an improved friction surfacing method to produce a surfaced layer on a substrate using powder material which produces surface deposits with very low dilution using powder materials. A still another object of the invention is to propose an improved friction surfacing method including a tool to produce a surfaced layer on a substrate using powder material which is simple and economic. Brief description of the accompanying drawings Fig-1 a schematic diagram showing the details of a tool according to the invention. Fig-2 a schematic representation of the operating principle of the method according to the Invention. Description of a preferred embodiment of the invention The present method involves use of a rotating tool of desired configuration as 3 shown in Figure-1. The tool body (1) has a hole (2) along its axis. The tip of the tool is profiled to enable transport and compaction of the powder material to form the deposit. The powder passes through the central hole (2) and a port (3) to a triangular profile (4). The rotating tool (1) initially approaches the surface (6) in which the material is to be deposited. Frictional heat is generated due the relative motion of the toot (1) under pressure and the stationary base material (6). A powder material (5) required to create the deposit is now fed through the hole (2) at the center of the tool (1). The bottom of the tool (1) has provisions for the discharge of the powder material (5) during the operation of the process, to a friction zone. The frictional heat generated softens the base material (6) and ) or the powder (5). The tool (1) enables the powder material (5) to be spread across the width of the tool (1). Simultaneously, the material is compressed, by a pressure generated in a vertical direction (8) on the tool (1) including the profile (5) of the tool (1) at its bottom side, into a compacted surface deposit (7). As the tool (1) moves in the lateral direction (8), a uniformly deposited surface is created. The deposit features can be controlled by controlling the feed rate of the powder (5) through the tool (1) at the friction interface. The principle of operation is shown in Fig.2. 4 WE CLAIM 1. An improved friction surfacing method to produce a surfaced layer on a substrate using powder material the method comprising : - providing a substrate having a base material (6); - providing a rotatable tool (1) having a profiled configuration (4) and a hole (2) to conduct a powder material therethrough; - rotating the tool (1) and moving the rotating tool (1) in a direction parallel to the substrate (6); - pressing the rotating tool (1) on the base material (6) and conducting a power material via the hole (2) in a direction towards the profiled configuration (4); wherein the friction pressure generating heat to transform the base and/or the power material to a plasticised condition which produces a compacted surface deposit (7) on the substrate. 2. The method as claimed in claim 1, wherein the powder material is 6 filter for creating the required deposit. 3. The method as claimed in claim 1 or 2, wherein the powder material has the same or different characteristics as compared to that of the base material (6). 5 4. The method as claimed in any of the preceding claims, wherein heat to transform the base and/or powder material is generated due to the friction between the relative motion of the rotating tool and the stationary surface to be deposited. 5. The method as claimed in claim 1, wherein the tool has atleast one delivery port (3) for discharge of the powder (5) from the central hole (2) to the triangular shaped profiles (5). 6. The method as claimed in claim 1, wherein the plasticised material is spread across the tool width by the rotation of the tool. 7. The method as claimed in claim 1, wherein one of the powder or the base material or both is plasticised depending upon their individual plasticizing temperature. 8. The method as claimed in claim 7, wherein the spreaded powder is compacted by the compressive action and the triangular profiles (5) of the tool (1) on the base material (6). 9. The method as claimed in claim 1, wherein the method is adaptable for multi layer surfacing. 10. An improved friction surfacing method to produce a surfaced layer on a substrate using powder material as substantially described herein with reference to the accompanying drawings 6

Full Text

Field of Invention
The present invention relates to weld surfacing of a material with similar /
dissimilar material in the form of powders, using the heat generated by friction
between surfaces in relative motion under pressure. More particularly, the
present invention relates to an improved friction surfacing method including a
tool to produce a surfaced layer on a substrate using powder material.
Background of the invention
Surfacing is a welding technique applied to industrial components operating in
service conditions involving corrosive medium or various kinds of wear
mechanisms or their combinations. Depending on the intensity and severity of
the service environments, the operating surfaces are deposited with suitable
materials to provide adequate service life to the component. The thickness of
deposit depends upon the service, requirements.
Weld surfacing is a technology widely used for the manufacture of new
components including the repair and reclamation of serviced components. For
the purpose, several types of welding and spraying techniques are employed.
Several fusion welding techniques based on arc and/or gas flame are generally
preferred due to the associated lower cost and ease of application. However, the
arc welding techniques result in relatively thicker weld deposits and often require
multi-layer deposits due to the higher level of dilution as consequent upon high-
energy dissipation. This leads to higher consumption of welding consumables to
achieve the required deposit surface properties. Spraying techniques are suitable
for thinner surfaced layers. However while fusion welding produces strong
metallurgical bonds, arc and gas based spraying techniques using powder
material for creating the coated surface produce generally a mechanical bond
1

between the surfaced layer and the substrate. Hence, the surfaced layer may
get disbonded with the impact loading.
Patent No. EP0474455 discloses a process for surfacing of materials using
frictional heat generated by moving surfaces in contact under pressure. The
process involves the use of a rotating consumable in the form of a rod. The rod
is pressed against the material to be surfaced raising the temperature of the rod
material and / or the base metal to their plastic temperature. As the rotating
tool moves in a linear direction, the plasticised material of the tool is transferred
to the member being surfaced and forms a deposited layer.
Patent No. U52005000424 describes a method for the formation of a deposit of
special characteristics using high velocity hot gas and powder filler material. The
powder particles heated to high temperature by the high velocity hot gas
impinge on the surface of the material on which the deposit is being created.
The impinging particles are mechanically locked on to the surface and between
themselves, resulting on a surface deposited layer.
All the prior art methods however entails defects like porosity in the weld
deposit, material loss, lack of proper bonding, improper thickness and bead
appearance. Further, such processes require costly and Intricate equipment.
Objects of the Invention
It is an object of the invention to propose an improved friction surfacing method
to produce a surfaced layer on a substrate using powder material which
eliminates the disadvantages of the prior art.
2

Another object of the invention is to propose an improved friction surfacing
method to produce a surfaced layer on a substrate using powder material which
makes use of powder fillers to produce thin layers of deposits.
A further object of the invention is to propose an improved friction surfacing
method to produce a surfaced layer on a substrate using powder material which
is capable of producing a thin deposit with good bonding over a wider area on a
substrate using multiple adjacent passes.
A still further object of the invention is to propose an improved friction surfacing
method to produce a surfaced layer on a substrate using powder material which
produces surface deposits with very low dilution using powder materials.
A still another object of the invention is to propose an improved friction surfacing
method including a tool to produce a surfaced layer on a substrate using powder
material which is simple and economic.
Brief description of the accompanying drawings
Fig-1 a schematic diagram showing the details of a tool according to the
invention.
Fig-2 a schematic representation of the operating principle of the method
according to the Invention.
Description of a preferred embodiment of the invention
The present method involves use of a rotating tool of desired configuration as
3

shown in Figure-1. The tool body (1) has a hole (2) along its axis. The tip of
the tool is profiled to enable transport and compaction of the powder material to
form the deposit. The powder passes through the central hole (2) and a port (3)
to a triangular profile (4). The rotating tool (1) initially approaches the surface
(6) in which the material is to be deposited. Frictional heat is generated due the
relative motion of the toot (1) under pressure and the stationary base material
(6). A powder material (5) required to create the deposit is now fed through the
hole (2) at the center of the tool (1). The bottom of the tool (1) has provisions
for the discharge of the powder material (5) during the operation of the process,
to a friction zone. The frictional heat generated softens the base material (6)
and ) or the powder (5). The tool (1) enables the powder material (5) to be
spread across the width of the tool (1).
Simultaneously, the material is compressed, by a pressure generated in a vertical
direction (8) on the tool (1) including the profile (5) of the tool (1) at its bottom
side, into a compacted surface deposit (7). As the tool (1) moves in the lateral
direction (8), a uniformly deposited surface is created. The deposit features can
be controlled by controlling the feed rate of the powder (5) through the tool (1)
at the friction interface. The principle of operation is shown in Fig.2.
4

WE CLAIM
1. An improved friction surfacing method to produce a surfaced layer on a
substrate using powder material the method comprising :
- providing a substrate having a base material (6);
- providing a rotatable tool (1) having a profiled configuration (4)
and a hole (2) to conduct a powder material therethrough;
- rotating the tool (1) and moving the rotating tool (1) in a direction
parallel to the substrate (6);
- pressing the rotating tool (1) on the base material (6) and
conducting a power material via the hole (2) in a direction towards
the profiled configuration (4); wherein the friction pressure
generating heat to transform the base and/or the power material to
a plasticised condition which produces a compacted surface
deposit (7) on the substrate.
2. The method as claimed in claim 1, wherein the powder material is 6 filter
for creating the required deposit.
3. The method as claimed in claim 1 or 2, wherein the powder material has
the same or different characteristics as compared to that of the base
material (6).
5

4. The method as claimed in any of the preceding claims, wherein heat to
transform the base and/or powder material is generated due to the
friction between the relative motion of the rotating tool and the stationary
surface to be deposited.
5. The method as claimed in claim 1, wherein the tool has atleast one
delivery port (3) for discharge of the powder (5) from the central hole (2)
to the triangular shaped profiles (5).
6. The method as claimed in claim 1, wherein the plasticised material is
spread across the tool width by the rotation of the tool.
7. The method as claimed in claim 1, wherein one of the powder or the base
material or both is plasticised depending upon their individual plasticizing
temperature.
8. The method as claimed in claim 7, wherein the spreaded powder is
compacted by the compressive action and the triangular profiles (5) of the
tool (1) on the base material (6).
9. The method as claimed in claim 1, wherein the method is adaptable for
multi layer surfacing.
10. An improved friction surfacing method to produce a surfaced layer on a
substrate using powder material as substantially described herein with
reference to the accompanying drawings

6

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Patent Number

259557

Indian Patent Application Number

245/KOL/2006

PG Journal Number

12/2014

Publication Date

21-Mar-2014

Grant Date

18-Mar-2014

Date of Filing

23-Mar-2006

Name of Patentee

BHARAT HEAVY ELECTRICALS LIMITED

Applicant Address

REGIONAL OPERATIONS DIVISION (ROD), PLOT NO :9/1, DJBLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITOY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI-110049

Inventors:

#	Inventor's Name	Inventor's Address
1	KRISHNASWAMY PADMANABAN	WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED, TIRUCHIRAPPALLI-620 014, TAMIL NADU, INDIA
2	GANAPATHY UMASHANKER	WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED, TIRUCHIRAPPALLI-620 014, TAMIL NADU, INDIA

PCT International Classification Number

N/A

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA