powder metallurgy ppt
TRANSCRIPT
Powder MetallurgyPowder Metallurgy
SUBMITTED BY INDRESH KUMAR BAIS ROLL NO. 11031M02018
OutlineOutline
IntroductionIntroduction
Powder ManufacturingPowder Manufacturing
Powder Metallurgy ProcessPowder Metallurgy Process
SinteringSintering
Other Powder Metal ProcessesOther Powder Metal Processes
Powder Metal ProductsPowder Metal Products
Powder Metallurgy DesignPowder Metallurgy Design
IntroductionIntroduction
Powder metallurgy is a Powder metallurgy is a processprocess by by which fine powdered materials are which fine powdered materials are blended, pressed blended, pressed into a into a desired desired shapeshape, and then , and then heated to bond heated to bond surfacessurfacesTypically used when Typically used when large large amounts amounts of of small, intricate parts small, intricate parts withwith high precision high precision are required are requiredLittle material waste Little material waste and and unusual unusual mixtures mixtures can be utilizedcan be utilizedUsed for parts in the automotive Used for parts in the automotive industry, household appliances, industry, household appliances, and recreational equipmentand recreational equipment
Powder MetallurgyPowder Metallurgy
MetalMetal
PowderPowder
Metal ProductMetal Product
Examples of Powder Examples of Powder Metal ProductsMetal Products
GearsGears
CamsCams
CranksCranks
BearingsBearings
Roller bearing cagesRoller bearing cages
HousingsHousings
Light bulb filamentsLight bulb filaments
Sprinkler mechanismsSprinkler mechanisms
Powder Metallurgy Powder Metallurgy ProcessProcess
Powder ManufacturingPowder Manufacturing
Conversion of molten metal to Conversion of molten metal to powderpowder
AtomizationAtomization
Powder Metal MaterialsPowder Metal Materials
ElementalElemental
A pure metal, most commonly A pure metal, most commonly iron, aluminum or copperiron, aluminum or copper
PrealloyedPrealloyed
An alloy of the required An alloy of the required composition, most commonly composition, most commonly copper alloys, stainless steel copper alloys, stainless steel or high-speed steelor high-speed steel
Powder ManufacturingPowder Manufacturing
Other methods of producing Other methods of producing powder:powder:
- Chemical reduction of Chemical reduction of particulate compoundsparticulate compounds
- Electrolytic depositionElectrolytic deposition- Pulverization or grinding of Pulverization or grinding of
brittle materialsbrittle materials- Thermal decompositionThermal decomposition- Precipitation from solutionsPrecipitation from solutions- Condensation of metal vaporsCondensation of metal vapors
Atomization
Atomization is accomplished by forcing a molten metal stream through an orifice at moderate pressures. A gas is introduced into the metal stream just before it leaves the nozzle, serving to create turbulence as the entrained gas expands (due to heating) and exits into a large collection volume exterior to the orifice. The collection volume is filled with gas to promote further turbulence of the molten metal jet. On Earth, air and powder streams are segregated using gravity or cyclonic separation. Most atomised powders are annealed, which helps reduce the oxide and carbon content. The water atomized particles are smaller, cleaner, and nonporous and have a greater breadth of size, which allows better compacting. The powders produced through this method are normally of spherical or pear shape. Usually, they also carry a layer of oxide over them.
Blending and MixingBlending and Mixing
BlendingBlending
Combining powders of the same material Combining powders of the same material but possibly different particle sizesbut possibly different particle sizes
MixingMixing
Combining powders of different materialsCombining powders of different materials
CompactionCompaction
High pressure is applied to squeeze High pressure is applied to squeeze the powder into the desired shapethe powder into the desired shape
SinteringSintering
Heats the powder below the melting Heats the powder below the melting point to allow solid-state diffusion point to allow solid-state diffusion and bond the particles togetherand bond the particles together
SinteringSintering
Other Powder Metal Other Powder Metal ProcessesProcesses
Cold Isostatic PressingCold Isostatic Pressing
Hot Isostatic PressingHot Isostatic Pressing
Injection MoldingInjection Molding
Powder RollingPowder Rolling
Powder ExtrusionPowder Extrusion
Plasma SprayingPlasma Spraying
Injection MoldingInjection Molding
The powder is mixed with a binder The powder is mixed with a binder and molded, and the binder is and molded, and the binder is removed before sinteringremoved before sintering
Powder RollingPowder Rolling
Powder is compressed in a rolling mill Powder is compressed in a rolling mill to form a stripto form a strip
Powder Metal ProductsPowder Metal Products
1.1. Porous or permeable Porous or permeable productsproducts
2.2. Products of complex shapesProducts of complex shapes3.3. Products made of materials Products made of materials
that are difficult to machine or that are difficult to machine or have high melting pointshave high melting points
4.4. Products which require the Products which require the combined properties of combined properties of multiple materialsmultiple materials
5.5. Products in which powder Products in which powder metallurgy produces superior metallurgy produces superior propertiesproperties
Powder Metallurgy Powder Metallurgy DesignDesign
1.1. The shape must permit removal The shape must permit removal from the diefrom the die
2.2. The shape should not have thin The shape should not have thin walls or sharp cornerswalls or sharp corners
3.3. The shape should permit the The shape should permit the construction of strong toolingconstruction of strong tooling
4.4. The shape of the part should be The shape of the part should be within the thickness range for within the thickness range for which the powder can be properly which the powder can be properly compactedcompacted
5.5. The part should have as few The part should have as few changes in section thickness as changes in section thickness as possiblepossible
Powder Metallurgy Powder Metallurgy AdvantagesAdvantages
1.1. Elimination/reduction of Elimination/reduction of machiningmachining
2.2. High production ratesHigh production rates
3.3. Complex shapes can be Complex shapes can be producedproduced
4.4. Wide composition variations Wide composition variations are possibleare possible
5.5. Wide property variations are Wide property variations are possiblepossible
6.6. Scrap is eliminated or Scrap is eliminated or reducedreduced
Powder Metallurgy Powder Metallurgy DisadvantagesDisadvantages
1.1. Inferior strength propertiesInferior strength properties
2.2. Relatively high die costRelatively high die cost
3.3. High material costHigh material cost
APPLICATIONAPPLICATION
••Bearing and filteringBearing and filtering
••Complex shape Complex shape
componentscomponents
••Automotive Automotive
componentscomponents
••Grinding wheelGrinding wheel