53005236 Powder Metallurgy Seminar Gautam Copy

7/29/2019 53005236 Powder Metallurgy Seminar Gautam Copy

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Powder Metallurgy- An insightBy

GAUTAM SHARMA1DA07ME023

DEPARTMRNT OF MECHANICAL ENGG.

DR.AMBEDKAR INSTITUTE OF TECHNOLOGY

BANGALORE-56


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Powder Metallurgy (P/M )Introduction

History

General Summary of the Science of P/M

1.powder production2.powder compaction

3.sintering/ infiltration

Powder metallurgy products

Applications and market

FeasibilityConclusions


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IntroductionPowder metallurgy is the manufacturing process used to

fabricate finished products by the method of compaction of

metal powders and further processing to achieve reqd.

properties.

Current feasible examples of its use are:

Connecting rods of bugatti and jaguars

Use in Automotive industry

Nacelle frame of F-22 raptor Precision equipments and biomedical industry


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HistoryEarly 3000 B.C. a crude form of powdermetallurgy in Egypt

Early 20th Centurycopper coins andmedallions, and tungsten wires

1920s tungsten carbide cutting-tool tips,self-lubricating bearings

1960s full-density products emerged.1970s high-performance superalloycomponents: aircraft turbine engine parts.

1980s the commercialization of rapidlysolidified and amorphous powders and thedevelopment of P/M injection moldingtechnology

After 2000- growing dependence ofautomotive and precision industry.


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G eneral S ummary of The S cience of P/MSTEPS:

a) Powder Production

b) Powder Consolidation

c) Sintering d) Finishing operations


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Powder ProductionAtomizat ion

o Electrolytic, precipitationo Mechanical

o Chemical, reduction

Powder Production


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Powder Production

Disintegration of liquid stream by a second fluid

Gas Atomization

Spherical powder particles

Good "flowability"

Water Atomization:

Irregular powder particles

Good compactability

Powder Production by Atomization


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Atomization SchematicsWater Atomization Induction Coil Gas Atomization

Water Water

Powder Production


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Powder Production Vertical G as Atomizer


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Powder shapes and sizes Chemical: Sponge Iron-

Reduced Ore

Electolytic: Copper

Mechanical: Milled

Aluminum Powder Water Atomization : Iron

Gas Atomization: Nickel-Base Hardfacing Alloy

Powder Production


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Gas Atomized

Silver Alloy

Powder Production


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WaterAtomized

Copper Alloy

Powder Production


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Impart shape to net or near net to powder mass

Net Shape:

Die Compaction

MIM (Metal Injection Molding)

Near Net Shape:

CIP (Cold Isostatic Pressing)

Hot Pressing

Extrusion

Rolling

Powder Consolidation

Consolidation


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Use water atomized powder (irregular shape)

Rigid tooling: tool steel, WC/Co

Pressures up to 60 tons/square inch Production > 10,000 parts

High tolerance, 0.001 "/" possible

High productivity

Controlled porosity, density (85% to 90%)

D ie Compaction

P d C lid i


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Axis-symmetric

No undercuts

No off-axis attributesL/D


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M IM (Metal Injection M olding) Plastic Injection Molding + Powder Metallurgy (P/M)

Complex Shapes

High density metal parts (> 95%)

Economy of Scale (high productivity)

Good tolerance, .003 "/" possible, .005-.008 "/" typ.

Competes wi th inv estment cast ing

and discrete machining


P d C lid ti


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S chematic O f MIMPowder Consolidation

Sintering


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SinteringHeat treatment to promote

Metallurgical integrity

Metallurgical Bonding

Densification (shrinkage)

Pore Elimination

Sintering

Sintering furnace

Sintering


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Sintering

infilt tion


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Infiltration

Infiltration is the process wherein a slug of low melting pointmetal is placed against the sintered parts and then theassembly is heated to a temperature sufficient to melt the slug.The slug infiltrates the pores, to produce a pore free parthaving good density and strength.

Advantages of infiltration are that high strength and density isachieved and pores are filled up, reducing corrosion. Somebearing materials are formed in this way.

infiltration

Products


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Powder M etallurgy Products Porous or permeable products

Oil-impregnated bearings Products of complex shapes that would require considerable machining

when made by other processes

complex shapes such as pawls, cams, and small activating levers

Products made from materials that are difficult to machine or with highmelting points

tungsten lamp filaments and tungsten carbide cutting tools Products where the combined properties of two or more metals are

desired

bearings made of graphite combined with iron or copper

Electrical contacts often combine copper or silver with tungsten, nickelor molybdenum

Products here the powder metallurgy process produces clearly superiorproperties

In areas of critical importance such as aerospace applications

Products

Applications


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P/M . A pplications and M arkets Automotive applications

Aerospace applications

Advanced composites

Magnetic materials Metalworking tools

A variety of biomedical

and dental applications

Applications

Applications


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Porous MetalsOil-impregnated Porous Bronze Bearings

Metal filters

Applications

Applications


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Automotive Industry

Automotive gears

Journal bearings

Connecting rods

Applications

Applications


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C E RM E T cutting tools(Ceramic-Metal composite)Microstructure: ceramic particles in metal matrix

Cermet-tipped saw blade for long

Cermet cutting inserts for lathe

Applications

Applications


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B iomedical and O thers:

KNEE CAPS WITHLUBRICATION

HIGH DENSITY GOLFSTICKS

OTHER HIGH PRECISION

AND SURGICALEQUIPMENTS

Applications

Applications


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Better material utilization

Fewer tool sets

Reduction of secondary machiningoperations

Large end bearing bore and mating flats Eliminate balancing

Cost saving in case of large productionvolume

P/M Press-S inter-Forgevs. Power Forge

Applications


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Feasibility of P/M ProductsCasting, Forging, Machining, P/M, etc:

Which method to choose?

Quality, Quantity, Tolerance,

Geometry, Material, Environment,

Labor quantity, Skill level, Equipment,

Etc

But MOST IMPORTANTLY..


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LOWEST

COST!


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Potential cost savingPart ( in production of F-

22 raptor)Weight( kg) Cost

saving

(%)Forged P/M Final part

Fuselage brace 2.8 1.1 0.8 50

Engine mount support 7.7 2.5 0.5 20

Arrestor hook support 79.4 25.0 12.9 25

Nacelle frame 143 82 24.2 50


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ConclusionsAdvantages:

Elimination or reduction ofmachining

High Production Rates

Complex Shapes can be

Produced Wide Variations in

Compositions are Possible

Wide Variation in

Properties are Available

Scrap is Eliminated or

Reduced

Disadvantages:

Inferior Strength Properties

Relatively High Die Cost

High Material Cost

Design Limitations

Density Variations ProduceProperty Variations

Health and Safety Hazards

53005236 Powder Metallurgy Seminar Gautam Copy

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