Abstract:
Sc
2W
3O
12, which exhibits excellent anisotropic negative thermal expansion was synthesized using solid-state reaction. Sc
2W
3O
12/ZrO
2 composites were prepared by mixing ZrO
2 and Sc
2W
3O
12 at different volume ratios and sintered at 1200 ℃ for 10 h. The crystal structure, fracture surface morphology and thermal expansion properties of the synthesized samples were characterized by XRD, SEM, EDS and dilatometer. The results indicate that the obtained samples contain only orthorhombic Sc
2W
3O
12 and monoclinic ZrO
2 phase. All the thermal expansion properties of Sc
2W
3O
12/ZrO
2 composites are linear from 30 ℃ to 600 ℃, and their thermal expansion coefficients can be controlled as positive, negative or even zero by adjusting the volume fraction of Sc
2W
3O
12. 60%Sc
2W
3O
12/ZrO
2 composite shows almost zero thermal expansion, and its average thermal expansion coefficient is 0.026×10
-6 ℃
-1 from 30 ℃ to 600 ℃.