Deformation processes of
porous metals and metallic
foams
-Review paper by Hiroshi Utsunomiya and
Ryo Matsumoto
1
Introduction: What are Porous
metals and Metallic foams?
• Porous metals are metals having large volume of
porosities, whi...
Properties of Porous
Metals
• Lightweight structure
• Energy absorber
• High temperature resistant
• Heat exchanger
• Biom...
Advantages of forming of
porous metals
• Forming to desired shape
• Control of porosity and morphology
• Work hardening of...
Advantages of forming of
porous metals
1. Forming to desired shape
• Cutting and machining are not easy because
porous met...
Advantages of forming of
porous metals
• Hence, we need to establish shaping technology
such as rolling, forging and bendi...
Advantages of forming of
porous metals
• Since, its characteristics cannot be perfectly
defined, the term ‘elongation effi...
Advantages of forming of
porous metals
2. Control of porosity and morphology
• High application of stress results in great...
Advantages of forming of
porous metals
3. Work hardening of matrix
• The applications to structural components have
been l...
Advantages of forming of
porous metals
• This process of fabrication not at very high
temperatures, increases specific str...
Advantages of forming of
porous metals
4. Improvements in properties
• Cold rolling increases the strength of the metal
du...
Advantages of forming of
porous metals
5. Unusual microstructure
• Heavy reduction and rolling forces the pores to
close b...
Advantages of forming of
porous metals
13
Advantages of forming of
porous metals
14
Lotus-type porous copper and nonporous Cu plates
were cold rolled with 90% reduc...
Advantages of forming of
porous metals
6. Forming complicated shapes
• Porous metals can shape complicated sections
wherea...
Advantages of forming of
porous metals
• Profiled strips prepared by simple grooved rolling
have certain defects.
• This i...
Advantages of forming of
porous metals
• Lotus-type porous coppers with one-dimensional
elongated pores were formed into T...
Conclusion
• It is evident that there are some applications that
are attainable using porous metals only and not
solid con...
Conclusion
• Deformation of these porous metals can improve
various properties.
• Also, porous metals may prove advantageo...
Bibliography
• Review paper:
http://www.sciencedirect.com/science/article/pii/S2211812814009791
• References:
1. https://e...
21
Thank You 
of 21

Porous materials and metallic foams

Deformation processes of porous metals and metallic foams. Based on a Review Paper.
Published on: Mar 4, 2016
Published in: Engineering      
Source: www.slideshare.net


Transcripts - Porous materials and metallic foams

  • 1. Deformation processes of porous metals and metallic foams -Review paper by Hiroshi Utsunomiya and Ryo Matsumoto 1
  • 2. Introduction: What are Porous metals and Metallic foams? • Porous metals are metals having large volume of porosities, while the terms foamed metal or metallic foams applies to porous metals produced with processes where foaming take place. • The mechanical properties cannot be described since the volume constancy is not satisfied. 2
  • 3. Properties of Porous Metals • Lightweight structure • Energy absorber • High temperature resistant • Heat exchanger • Biomaterial • Filter 3
  • 4. Advantages of forming of porous metals • Forming to desired shape • Control of porosity and morphology • Work hardening of matrix • Improvements in properties • Unusual microstructure • Forming of complicated shapes 4
  • 5. Advantages of forming of porous metals 1. Forming to desired shape • Cutting and machining are not easy because porous metals easily collapse under compressive force. • Porous metals are highly ductile. • Welding and joining of porous metals are also difficult because real contact area on the interface is limited for sufficient bonding. 5
  • 6. Advantages of forming of porous metals • Hence, we need to establish shaping technology such as rolling, forging and bending, of porous metals for industrial applications. • However, it is not possible to predict deformation characteristics of porous metals precisely, because the volume is not constant due to pore closure. 6
  • 7. Advantages of forming of porous metals • Since, its characteristics cannot be perfectly defined, the term ‘elongation efficiency’ is defined. • It is the ratio of longitudinal strain divided by thickness strain. • The volume change decreases with increasing density. • It is used to express the contribution of volume change on deformation characteristics. 7
  • 8. Advantages of forming of porous metals 2. Control of porosity and morphology • High application of stress results in greater decrease in porosity. Larger pores tend to decrease more in size. • However, this can be controlled by metal forming processes like the ECEA process. • To control mechanical properties there can be improvements in the Nonporous skin. • Also, this is effective to make the deformation more uniform. 8
  • 9. Advantages of forming of porous metals 3. Work hardening of matrix • The applications to structural components have been limited because the strength per weight is not as high as that of conventional wrought metals. • If high strength porous metals are to be produced, fabrication at high temperatures should be avoided. 9
  • 10. Advantages of forming of porous metals • This process of fabrication not at very high temperatures, increases specific strength, but the productivity is low. • This indicates that deformation processes can increase specific strength although it decreases porosity. • For lotus-type porous metals, bubbling process for metallic foams and one- directional solidification are necessary for pore formation. 10
  • 11. Advantages of forming of porous metals 4. Improvements in properties • Cold rolling increases the strength of the metal due to work hardening of matrix but decreases porosity. • But, cold rolling also enhances other properties of porous metals. • It was experimentally proved that cold rolling increases the sound absorbing ability of aluminum foam in a certain frequency range. 11
  • 12. Advantages of forming of porous metals 5. Unusual microstructure • Heavy reduction and rolling forces the pores to close by introducing bonding interface. • Mis-orientation of the bonded interface is higher in high-angle grain boundary (HAGB) and low-angle grain boundary (LAGB) than normal grain boundaries because it is mechanically introduced by bonding of internal surfaces surrounding pore. 12
  • 13. Advantages of forming of porous metals 13
  • 14. Advantages of forming of porous metals 14 Lotus-type porous copper and nonporous Cu plates were cold rolled with 90% reduction in thickness.
  • 15. Advantages of forming of porous metals 6. Forming complicated shapes • Porous metals can shape complicated sections whereas non-porous metals cannot. • Eg: Profiled strips used in electric parts like lead frames for power transistors. • These are narrow metal sheets in which thickness is distributed stepwise in the width direction. • Profiled strips can reduce weights of products and manufacturing processes. 15
  • 16. Advantages of forming of porous metals • Profiled strips prepared by simple grooved rolling have certain defects. • This is because difference in elongation, in the rolling direction, between thick and thin parts is excessive. • But if Profiled strips are made of flat porous strips, there are no shape defects. 16
  • 17. Advantages of forming of porous metals • Lotus-type porous coppers with one-dimensional elongated pores were formed into T-shaped strips by one-pass cold rolling. 17
  • 18. Conclusion • It is evident that there are some applications that are attainable using porous metals only and not solid convectional metals. • Use of porous metals has advantages such as the deformability of porous metals is generally high and sufficient for bulk metal forming. • However, the disadvantage is that the volumetric change is quite large. 18
  • 19. Conclusion • Deformation of these porous metals can improve various properties. • Also, porous metals may prove advantageous for future industrial applications. • Till now, everything is based on trial and error methods. There could be some theoretical or numerical models, which might help us predicting various parameters. 19
  • 20. Bibliography • Review paper: http://www.sciencedirect.com/science/article/pii/S2211812814009791 • References: 1. https://en.wikipedia.org/wiki/Metal_foam 2. http://www.helmholtz- berlin.de/media/media/spezial/people/banhart/html/A- Journals/open/postprint/a122_lefebvre2008.pdf 3. https://books.google.co.in/books?id=yeUM3eEF4jMC&pg=PA251&lpg =PA251&dq=future+scope+of+the+use+of+porous+metals&source=bl &ots=iQVmrOrpGF&sig=1GYQTncI9n3zU- Dh8FCuGuh7OxQ&hl=en&sa=X&ved=0CDAQ6AEwA2oVChMIno3-- 5qRyAIVTwuOCh2KsQ8V 20
  • 21. 21 Thank You 

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