Screening of TiB2-based ternary composites for X-ray transparent heaters in high-pressure and high-temperature experiments

High-pressure and high-temperature (HPHT) experiments in large-volume presses (LVPs) benefit from reliable, available, and affordable heaters to achieve stable and homogeneous heating and, in some circumstances, X-ray transparency for monitoring of properties of an in situ experiment using X-ray diffraction and contrast imaging techniques. We have developed heaters meeting the above requirements, and we screen the ternary system TiB2–SiC–hexagonal (h)BN (denoted as TSB) to enable manufacture of X-ray transparent heaters for HPHT runs. Heaters fabricated using optimized TSB-631 (60%TiB2–30%SiC–10%hBN by weight) have been tested in modified truncated assemblies, showing excellent performance up to 22 GPa and 2395 K in HPHT runs. TSB-631 has good ceramic machinability, outstanding reproducibility, high stability, and negligible temperature gradient for runs at 3–7 GPa with cell assemblies with truncated edge lengths of 8–12 mm. The fabricated heaters not only show excellent performance in HPHT runs, but also demonstrate high X-ray transparency over a wide X-ray wavelength region, indicating potential applications for in situ X-ray diffraction/imaging under HPHT conditions in LVPs and other high-pressure apparatus.