POROSITY DEVELOPMENT DURING HEAT TREATMENT OF ALUMINUM-LITHIUM ALLOYS

J. Papazian , J. Wagner , W. Rooney

The development of a sub-surface layer of porosity during heat treatment has been studied in a variety of Al-Li alloys. Pure binary Al-Li alloys and three commercial materials were heat treated in air, vacuum and hydrogen for various lengths of time. Subsequent metallographic sectioning and polishing revealed the presence of a band of pores in the near-surface region extending approximately 300 µm into the sample after a 16 h heat treatment. This band of porosity is thought to arise from a Kirkendall effect due to the loss of lithium during heat treatment of the sample. The evolution of the spatial distribution of these pores was characterized with a quantitative image analyzer. The effects of prior surface preparation were also determined. The results showed that structural defects influenced pore nucleation and that environmental factors were also significant. A simultaneous pore healing process also occurred immediately adjacent to the external surface.

Domaines: Articles anciens

J. Papazian, J. Wagner, W. Rooney. POROSITY DEVELOPMENT DURING HEAT TREATMENT OF ALUMINUM-LITHIUM ALLOYS. Journal de Physique Colloques, 1987, 48 (C3), pp.C3-513-C3-519. ⟨10.1051/jphyscol:1987359⟩. ⟨jpa-00226590⟩