Comparison of rare earth oxides on properties of vitrified diamond composites

- Proper CeO2 or Y2O3 additions improved the mechanical and thermal properties of vitrified diamond composites.
- Rare earth oxides could prompt the boron to diffuse into the diamond surface.
- CeO2 played greater impact than Y2O3 on diamond composites properties.

The role of rare earth oxides (CeO2 and Y2O3) in the microstructures and properties of vitrified diamond composites was comprehensively investigated. The results revealed that the incorporation of appropriate amounts of CeO2 or Y2O3 could not only decrease the refractoriness but also increase the fluidity of vitrified bonds. In comparison with composites containing Y2O3, composites doped with CeO2 possessed lower porosity and coefficient of thermal expansion. When adding 4 wt.% rare earth oxides, the flexural strength and thermal conductivity of composites containing CeO2 simultaneously achieved the maximums, 102.5 MPa and 4.37 W·m− 1·k− 1, respectively, which highly surpassed the values of composites without additives and composites containing Y2O3. In general, the difference of CeO2 and Y2O3 on properties of composites was mainly attributed to the different accumulation effects of corresponding cations. CeO2 played greater impact than Y2O3 on the properties of vitrified diamond composites.

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