A new method for solid‐state diffusion of boron atoms into powders of a multicomponent carbide

Abstract

Multicomponent boron‐containing carbide (ie, Zr‐Ti‐C‐B) composites show good ablation resistance. The present work is the first report to introduce the powder fabrication of Zr‐Ti‐C‐B using a new method for solid‐state diffusion of boron atoms. First, the nonstoichiometric carbide (ie, Zr0.8Ti0.2C0.8) with carbon vacancies was fabricated by free‐pressureless spark plasma sintering. Different boron sources such as B2O3, B, and B4C were used to react with the nonstoichiometric carbide. The Zr0.81Ti0.19C0.86B0.14 can be finally generated through the solid‐state diffusion of boron atoms using the B2O3 boron source at 1300°C followed by carbon thermal reduction using the phenolic resins at 1600°C.

Oxidation behavior of boron-containing (Zr,Ti)C x B y solid solution ceramics at 1600 °C in air

“…The as-synthesized (Zr,Ti)C x and (Zr,Ti)C x B y powders were utilized as raw materials for sintering (Zr,Ti)C x and (Zr,Ti)C x B y ceramics, both of which were single-phase solid solution with the FCC structure [21,25]. The preparation of the (Zr,Ti)C x solid solution powders used elemental powders as starting materials, including Zr (purity > 99.5 wt%, impurity Hf < 0.5 wt%, particle size ≤ 50 µm), Ti (purity > 99.5 wt%, impurity O < 0.2 wt%, H < 0.2 wt%, particle size ≤ 50 µm), and carbon (graphite, 99.95 wt%, 3 µm, Macklin Biochemical Co., Ltd., China).…”

“…They were fabricated by the modified SPS apparatus (HP D 25-3, FCT Systeme GmbH, Germany), and the details were reported in the prior work [21]. The (Zr,Ti)C x B y solid solution powders were synthesized using the (Zr,Ti)C x powders and B 2 O 3 (Aladdin, amorphous) as a boron source by solid-state diffusion of boron atoms, and the details were shown in the work [25].…”

“…The ablation behavior of C/C-(Zr 0.8 Ti 0.2 )C 0.74 B 0.26 had been systematically studied in the range of 2000-3000 ℃, whereas the oxidation behavior of (Zr,Ti)C x B y at a relatively low temperature (< 1800 ℃) has not been understood. In our recent work [25], single-phase (Zr,Ti)C x B y solid solution powders are successfully fabricated using solid-state diffusion of boron atoms. To fully understand the high-temperature oxidation of this new type of boron-containing carbide ceramics, this work is the first to investigate the oxidation behavior of the (Zr,Ti)C x B y solid solution block ceramics at high temperatures.…”