Porous Al alloys by local melting and diffusion of metal powders
- Univ. of Virginia, Charlottesville, VA (United States). Dept. of Materials Science and Engineering
A novel method exploiting local melt and diffusion induced porosity is described for producing porous Al alloys. Aluminum powder and zinc powder were blended and cold-compacted to a near net shape. A porous Al-Zn alloy component was then formed by annealing the material above the melting point of zinc but below the solidus temperature of the alloy. Pores were generated by the diffusion of molten Zn into the solid Al grains. The pore structure is shown to be determined by the volume fraction, distribution, and size of the Zn powders in the powder mixture, and by time and temperature of the annealing heat treatment. The pores can be further expanded by incorporating small amounts of titanium hydride into the powder blend and conducting the annealing treatment above the decomposition temperature of the titanium hydride (T > 447 C). Porosity levels of 45 vol.% have been achieved to date. This processing approach appears amenable to the production of sandwich panels with a gradient porosity core and fully dense face sheets, and is applicable to other solid solution systems.
- Sponsoring Organization:
- Defense Advanced Research Projects Agency, Arlington, VA (United States); Office of Naval Research, Washington, DC (United States)
- OSTI ID:
- 361823
- Report Number(s):
- CONF-980405--
- Country of Publication:
- United States
- Language:
- English
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