Enhancement of open cell aluminum foams through thermal evaporating Zn film

• Thermal evaporating technique was first used to enhance the aluminum foams.
• A homogeneous zinc coating was obtained.
• The yield strength of the samples could be increased by a factor of 14.

Relatively low mechanical properties of open cell aluminum foams have become a restrictive factor to their applications in engineering fields. To overcome this shortcoming, a surface enhancing method was investigated in the present study to coat a zinc film on the cell strut surface through thermal evaporating technology. The results show that the coated film obviously makes the foam enhanced and the compression yield strength is increased one order of magnitude higher than that of uncoated material. On the other hand, the mechanical characteristics of the foam has changed from ductile to brittle after the coating, represented by pronouncedly serrated stress-strain curves. This demonstrates that the mechanical behavior of the coated foam is to a great degree dominated by the film and the surface coating does be an effective way to modify the overall mechanical behavior of aluminum foams.