Metal Foam

Ryan McDonough

What is Metal Foam• An ultra high strength metal matrix

composite foam.• The material can be any type of metal • Even though it is metal it has

interconnecting hollow pores • Strong, light and somewhat elastic

How it Works• Today metal foam is thought to be used for bone implants

• With normally titanium rod implants the bone and the titanium rod have a different modulus of elasticity

• The metal foam and bone have the same modulus of elasticity

• Allows bone cells and blood vessels to grow into the pores of the metal foam

• Normal metal implants carry more of the weight of the body then the bone does and can cause the surrounding bone to die.

How its made• There are 2 ways to make the metal foam

• 1) Salt mold-

– involves pouring large grained salt into a mold, then the salt is heated and put under pressure so they fuse together

– Molten metal is then poured in the mold and fills in the spaces between the salt grains

– It is then cooled and dunked in water to dissolve the salt leaving only the metal foam

How its Made(continued)• 2) Plaster mold-

– An open cell plastic foam is used to begin the process

– The foam is filled with a dissolvable plaster making plastic beams inside the plaster

– The mold is then heated which melts the plastic

– Molten metal is then squeezed into the plaster mold using high pressure and a vacuum

– The plaster is then dissolved and the foam is done

Benefits/ Limitations

• Benefits– Less likely for the bone to reject the implant

– Use less of whatever metal that is being used

• Limitations– Takes a while to produce the foam

– The process is expensive

– Difficult to make

Sources• Vendra, L. "New Material Mimics Bone to Create Better Biomedical Implants." Science Daily: News & Articles in Science,

Health, Environment & Technology. Science Daily, 16 Feb. 2010. Web. 19 Nov. 2011. <http://www.sciencedaily.com/releases/2010/02/100216113603.htm>.

• Michaels, Bob. "Composite Metal Foam Material Could Be Tomorrow's Knee Cap | Qmed." Qmed | Medical Device Industry Supplier Directory. Qmed, Apr. 2010. Web. 19 Nov. 2011. <http://www.qmed.com/mpmn/article/composite-metal-foam-material-could-be-tomorrows-knee-cap>.

• Rugani, Lauren. "Metal Foam Could Build Better Bones, Car Bumpers." Science 2.0 - ® The World's Best Scientists, the Internet's Smartest Readers. Science 2.0, 19 Feb. 2010. Web. 19 Nov. 2011. <http://www.science20.com/futuro/metal_foam_could_build_better_bones_car_bumpers>.

• Kaiser, Tiffany. "Researchers Develop New Titanium Bone Implants." Daily Tech. Daily Tech, 23 Sept. 2010. Web. 19 Nov. 2011. <http://www.dailytech.com/Researchers+Develop+New+Titanium+Foam+Bone+Implants+/article19703.htm>.

• Morton, Todd. "Titanium Foam Scaffolds Made to Match Bone's Properties." Ars Technica. Ars. Web. 19 Nov. 2011. <http://arstechnica.com/science/news/2008/08/titanium-foam-scaffolds-made-to-match-bones-properties.ars>.

• "Metal 'foam' Developed for Bone Implants - UPI.com." Latest News, Latest News Headlines, News Articles, News Video, News Photos - UPI.com. UPI, 23 Sept. 2010. Web. 19 Nov. 2011. <http://www.upi.com/Science_News/2010/09/23/Metal-foam-developed-for-bone-implants/UPI-24901285293325/>.

• Curran, Dave. "People | Dave Curran | Metal Foams." Department of Materials Science & Metallurgy, University of Cambridge. Web. 19 Nov. 2011. <http://www.msm.cam.ac.uk/mmc/people/old/dave/dave.html>.