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Marco Actis Grande
Introduction to PM
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia
• Materials forming technique• “Create” powders (metallic & non-metallic)• Assemble them into artefacts of desired shape
• Cause the powder particles toadhere strongly to one another(usually at high temperature bymeans of a process calledsintering)
• Further processing or finishing
What is PM?
EPMA Powder Metallurgy Summer School 2016 - Valencia
Powder Metallurgy is acontinually and rapidly evolvingtechnology embracing mostmetallic and alloy materials,and a wide variety of shapes.PM is a highly developedmethod of manufacturingreliable ferrous and nonferrous parts. The EuropeanMarket alone has an annualturnover of over Six BillionEuros, with annual worldwidemetal powder productionexceeding one million tonnes.
What is PM?
EPMA Powder Metallurgy Summer School 2016 - Valencia
Once upon a time…
What is PM?
Sintering: a process involved in the heat treatment of“green” powder compacts at elevated temperatures, usuallyat T > 0.5Tm [K]. By means of this heat treatment a powdercompact is densified and gets the desired mechanicalproperties.
EPMA Powder Metallurgy Summer School 2016 - Valencia
The ISO definition of the term “sintering” states:
“The thermal treatment of a powder or compact at atemperature below the melting point of the main constituent,for the purpose of increasing its strength by bonding togetherof the particles.”
EPMA Powder Metallurgy Summer School 2016 - Valencia
Why PM?
• Highly developed method for manufacturing reliableferrous & non-ferrous parts
• Flexible range of Processes & Materials
• Wide variety of shapes & sizes
• Cost savings
• Linear combination of the former
EPMA Powder Metallurgy Summer School 2016 - Valencia
• Eliminates or minimizes machining by producing parts at, or closeto, final dimensions
• Eliminates of minimizes scrap losses by typically using more than97% of the starting raw material in the finished part.
• Permits a wide variety of alloy systems.• Produces good surface finishes.• Provides materials which may be heat-treated for increased strength
or increased wear resistance.• May provide controlled porosity for self-lubrication or filtration.• Facilitates the manufacturing of complex or unique shapes which
would be impractical or impossible with other metalworking processes.• Is suited to moderate to high volume component production
requirements.• Offers long-term performance reliability in critical applications.• Is cost-effective.
Why PM?
EPMA Powder Metallurgy Summer School 2016 - Valencia
An overall (and rough) comparison between differentmanufacturing techniques…
The PM process has:
• The highest rawmaterial utilisation (inmost cases over 95%)• The lowest energyrequirement per kg offinished part
Why PM?
EPMA Powder Metallurgy Summer School 2016 - Valencia
When PM?
Different production strategies can be at the basis of theuse of PM technology:
• High cost savings: large manufacturing lots, (relatively)complex shapes, small size parts
No improvement in properties
• Higher properties/performance rateUsually higher properties than alternativemanufacturing processes
• Unique way to manufacture
EPMA Powder Metallurgy Summer School 2016 - Valencia
Synchroniser hub
EPMA Powder Metallurgy Summer School 2016 - Valencia
PM process
EPMA Powder Metallurgy Summer School 2016 - Valencia
Forging and machining
EPMA Powder Metallurgy Summer School 2016 - Valencia
Forging and machining
PM process
43% energy saving
EPMA Powder Metallurgy Summer School 2016 - Valencia
Powder metallurgical
Conventional ingot
Conventional hot worked
Tool steels (I)
EPMA Powder Metallurgy Summer School 2016 - Valencia
non metallic inclusions
Carbide size andnetwork
Tool steels (II)
EPMA Powder Metallurgy Summer School 2016 - Valencia
Cemented carbides
EPMA Powder Metallurgy Summer School 2016 - Valencia
Bearings and Filters
EPMA Powder Metallurgy Summer School 2016 - Valencia
FAST techniques
www.ifam.fraunhofer.de
EPMA Powder Metallurgy Summer School 2016 - Valencia
History of (industrial) PM
W filament
Hardmetalsand self‐lubricatingbearings
Structuralparts MIM FAST Additive
Late 19thcentury
1920s 1940s Late 1980s 2000 2010
EPMA Powder Metallurgy Summer School 2016 - Valencia
• Conventional P/M (press and sinter)• Powder Injection Moulding• (Hot,Cold) Isostatic Pressing• Roll Compacting• FAST Techniques• Additive Manufacturing• …
(Main) PM Processes
EPMA Powder Metallurgy Summer School 2016 - Valencia
Rapid Prototyping
MIM
Low Complexity High
Cut
ting
tech
nolo
gies
Form
ing
tech
nolo
gies
PM (Press and sinter)
106
105
104
103
102
10
1
Par
ts p
er Y
ear
Pressure die casting
Investment casting
PM (and other) Processing
EPMA Powder Metallurgy Summer School 2016 - Valencia
Chemical methods
Solid State Reduction [Fe]
Electrolysis [Fe]
Reactions with gases[eg Carbonyl]
Hydrogen reduction[W from paratungstate]
Physical methods
Atomisation(fast solidification)
Mechanical methods:Crushing, milling
Mechanical alloying:milling
Common starting
EPMA Powder Metallurgy Summer School 2016 - Valencia
Press and sinter
EPMA Powder Metallurgy Summer School 2016 - Valencia
Uniaxial Compaction
Press
EPMA Powder Metallurgy Summer School 2016 - Valencia
Steels: 1100 – 1300 °CAl & alloys: 590 – 620 °CCu & alloys: 750 – 1000 °C
…and sinter
EPMA Powder Metallurgy Summer School 2016 - Valencia
Gaseous environments for sintering
• Chemically active: reducing
• for steels, carbon potential of the atmosphere should be in equilibrium with carbon content of the steel
• Much more demanding requirements for materials with greater affinity for oxygen,Al, stainless steel, etc
Atmospheres
EPMA Powder Metallurgy Summer School 2016 - Valencia
Alloying during sintering• pre-alloyed powders; hard but uniform
• mixed elemental powders; inter-diffusion during sintering generally not complete, providing non-uniform microstructures
Liquid phase sinteringOne phase melts. Lot of liquid cannot be allowed - part will slump
Liquid flows into available space and re-organises the solid particles
Diffusion is much faster in liquid.
Ex: Hard metals, WC with Co binder
EPMA Powder Metallurgy Summer School 2016 - Valencia
Metal injection moulding (MIM) is a manufacturing process which combines the versatility of plastic injection moulding with the strength and integrity of machined, pressed or otherwise manufactured small, complex, metal parts.
Metal Injection Moulding
EPMA Powder Metallurgy Summer School 2016 - Valencia
Isostatic pressing
ColdHot
EPMA Powder Metallurgy Summer School 2016 - Valencia
Cutting toolsHard metalCermetsDiamond tools
EPMA Powder Metallurgy Summer School 2016 - Valencia
Roll compaction
EPMA Powder Metallurgy Summer School 2016 - Valencia
EDC/EDS
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia
Additive Manufacturing
EPMA Powder Metallurgy Summer School 2016 - Valencia
Additive Manufacturing
EPMA Powder Metallurgy Summer School 2016 - Valencia
Additive Manufacturing
EPMA Powder Metallurgy Summer School 2016 - Valencia
DED Technology
PBF Technology
Additive Manufacturing
EPMA Powder Metallurgy Summer School 2016 - Valencia
EBM Technology
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia
Hydraulic manifold built using EBM technologyCourtesy: ORNL
Medical implant application using:(left) DMLS technology. (right) EBM technology
EPMA Powder Metallurgy Summer School 2016 - Valencia
A lightweight seat buckle with hollow structures was designed based on extensive FEA study to ensure enough strength against shock loading. The part was produced using DMLS Ti-6Al-4V alloy.
Replacement of a conventional steel buckle with hollow AM titanium buckle causes 85 g weight saving per buckle (55% weight reduction).
An Airbus A380 with 853 seats will result in a possible weight saving of 72.5 kg.
According to the project sponsor, Technology Strategy Board, United Kingdom, this weight saving translates to 3.3 million liters of fuel saving over the life of the aircraft that is equivalent to £2 million, while cost of making all the buckles using DMLS is only £165,000 .
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia
EPMA Powder Metallurgy Summer School 2016 - Valencia