Dilatometry of Refractory Metals and Alloys Using Multi-Wavelength Laser Shadowgraphy of Filament Samples
H. S. Ayoub, A. F. El-Sherif, H. H. Hassan, S. A. Khairy and Y. H. Elbashar
In the present work, a new technique for measuring the linear thermal expansion of refractory metals and alloys over their entire temperature range from room to near melting. The technique is based on generating multi-wavelength laser shadowgraphs for filament wire samples under gradual heating, and measuring the dimensional changes from its shadowgraphs using digital camera. The samples are clamped from both ends and joule heated by direct current under vacuum. The measurements are non-contact and accurate, enabling low cost dilatometric measurements that help in future synthesis and test of new grade of refractory materials, used as plasma facing material in nuclear fusion reactor, or special super alloys for high temperature applications were thermal structural stability are required.
Keywords: Elevated temperatures, Filament dilatometry, Linear expansion, laser shadowgraphy, Refractory materials