powder metal processing
DESCRIPTION
Powder Metal Processing. Manufacturing Processes By: Dr.Behzad Heidarshenas. Outline. Introduction Powder Manufacturing Powder Metallurgy Process Sintering Other Powder Metal Processes Powder Metal Products Powder Metallurgy Design. Powder Metallurgy. Powder Metallurgy. Metal Powder - PowerPoint PPT PresentationTRANSCRIPT
Powder Metal Powder Metal ProcessingProcessing
Manufacturing Manufacturing ProcessesProcesses
By:By:
Dr.Behzad HeidarshenasDr.Behzad Heidarshenas
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
Powder MetallurgyPowder Metallurgy
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 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
Conversion of molten metal to Conversion of molten metal to powderpowder
AtomizationAtomization
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
Particle ShapeParticle Shape
Particle SizeParticle Size
The process of separating particles The process of separating particles by size is called classificationby size is called classification
Particle SizeParticle Size
Micrograph of screened powder particles, showing that particles may be longer than the mesh is wide
Particle SizeParticle Size
void
smaller, more numerous voids
voids filled by smaller particles, small voids remain
Mixing particles of different sizes allows decreased porosity and a higher packing ratio
Powder Metallurgy Powder Metallurgy ProcessProcess
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
Example of a Powder Example of a Powder PressPress
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
Isostatic PressingIsostatic Pressing
Uses pressurized fluid to compress the Uses pressurized fluid to compress the powder equally in all directionspowder equally in all directions
Cold Isostatic PressingCold Isostatic PressingCompaction performed at room Compaction performed at room temperaturetemperature
Hot Isostatic PressingHot Isostatic PressingPerformed at high temperatures and Performed at high temperatures and pressurespressures
Example of an Isostatic Example of an Isostatic PressPress
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 ExtrusionPowder Extrusion
The powder can be extruded within a The powder can be extruded within a container or after being formed into container or after being formed into billets billets
Plasma SprayingPlasma Spraying
Uses a plasma arc to propel molten Uses a plasma arc to propel molten droplets at a surface at a high droplets at a surface at a high velocity, forming a high-density velocity, forming a high-density structurestructure
Plasma SprayingPlasma Spraying
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
Diagram of particles in sintering, showing the possible movements of atoms
SinteringSintering
SinteringSintering
Sintering Production Sintering Production LinesLines
Examples of Sintering Examples of Sintering Production LinesProduction Lines
SinteringSintering
Strength of sintered structures as related to density, showing that the strength is higher when the density
is higher (less residual porosity)
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 DesignDesign
6.6. Parts can be designed to take Parts can be designed to take advantage of the capabilities of advantage of the capabilities of the powder metallurgy processthe powder metallurgy process
7.7. The design should be consistent The design should be consistent with available equipmentwith available equipment
8.8. Consideration should be given for Consideration should be given for product tolerancesproduct tolerances
9.9. Design should consider the Design should consider the dimensional changes that occur dimensional changes that occur after pressing, such as shrinkage after pressing, such as shrinkage during sinteringduring sintering
Powder Metallurgy Powder Metallurgy DesignDesign
Powder Metallurgy Powder Metallurgy DesignDesign
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
SummarySummary
Powder metallurgy can create Powder metallurgy can create parts that would otherwise be parts that would otherwise be difficult to form, including those difficult to form, including those with complex shapes or with complex shapes or porosityporosity
Sintering bonds particles Sintering bonds particles together by allowing atoms to together by allowing atoms to move, forming necks and grain move, forming necks and grain boundaries between the boundaries between the particlesparticles