The thermal expansion of the directionally solidified AI-CuAI2 eutectic
- Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering
- Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials and Molecular Research Division
In this paper, alloys of Al-CuAl2 eutectic composition were prepared from 99.999 pct pure materials and directionally solidified in a temperature gradient of about 45 °C/cm at different growth ratesR. The λ2R= constant relation was verified and lamellar spacings of 7.5, 3.5, 2.6, 1.8 and 1.4 μm were obtained. Dilatometer specimens were machined with axes aligned in the principal lamellae coordinate directions. Thermal expansion was measured by standard dilatometry (Cu standard) using a set point program cycling between room temperature and 500 °C. Thermal expansion of the directionally solidified Al-CuAl eutectic is greatest in the growth direction (in the plane of the lamellae), least in the tranverse direction (orthogonal to the growth direction in the plane of the lamellae) and intermediate in the direction normal to the lamellae. Finally, the most significant finding of the study is that the thermal expansion increases with decreasing lamellar spacing between limits defined approximately by the thermal expansion of the CuAl2 phase alone and the predicted thermal expansion of an isotropic elastic model of the composite.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Contributing Organization:
- Univ. of California, Berkeley, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 1068161
- Report Number(s):
- LBL--10640
- Journal Information:
- Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 1 Vol. 12; ISSN 0360-2133
- Publisher:
- ASM International
- Country of Publication:
- United States
- Language:
- English
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