Effect of predeformation on the thermopower of AlCu alloy

✍ Scribed by F. Abd El-Salam; S.A. Khairy

• Publisher: Elsevier Science
• Year: 1986
• Weight: 482 KB
• Volume: 34
• Category: Article
• ISSN: 0001-6160
• DOI: 10.1016/0001-6160(86)90129-x

✦ Synopsis

Thermoelectric power (TEP) measurements

for Al4 wt% Cu alloy samples in the form of wires 0.5 mm diameter quenched then deformed torsionally to different degrees were carried out after isothermal annealing in the temperature range 383423 K. Precipitation of excess solute Cu atoms, as traced through TEP measurements was enhanced by predeformation and attained different stable sizes depending on the annealing temperatures as revealed by the observed final stable TEP values. The energy activating precipitation process (Q) was found to be deformation dependent. The time exponent 1.06 as calculated from the volume fraction of Cu atoms precipitated at a certain time t to form Guinier-Preston (GP) zones was found to be independent on predeformation over all the investigated temperature range and consisted with Hams theory for precipitation on dislocations.

The results were interpreted on the basis of the dominating and predeformation and the different contributions of the solute atoms when dispersed in the matrix or included in the formed GP zones to the measured TEP.