Composite foam made out of 100 percent steel using powder metallurgy technique.The metal foam is lighter than solid aluminium and can also be made of 100% steel.
The researchers suggest that the foam could be used for biomedical implants and help avoid the bone rejection that can result from more rigid implant materials, such as titanium. The rough surface of the foam would also foster bone growth into the implant, improving the strength of implant.
“When an orthopedic or dental implant is placed in the body to replace a bone or a part of a bone, it needs to handle the loads in the same way as its surrounding bone,” said Dr. Afsaneh Rabiei, an associate professor of mechanical and aerospace engineering. “If the modulus of elasticity of the implant is too much bigger than the bone, the implant will take over the load bearing and the surrounding bone will start to die,” Rabiei explains.
While titanium has a modulus of elasticity of approximately 100 GPa, the new composite foam has a modulus t has a modulus of between 10 and 30 GPa, the same as bone.
The research, “Evaluation of modulus of elasticity of composite metal foams by experimental and numerical techniques,” will be published in the March issue of Materials Science and Engineering. It was co-authored by Rabiei and former NC State PhD. student L. Vendra.