Ablation-resistant high-entropy carbide-high-entropy diboride-silicon carbide multiphase ceramic and preparation thereof

Patent metadata

Field	Value
Publication number	US-12503404-B2
Application number	US-202318153117-A
Country	US
Kind code	B2
Filing date	Jan 11, 2023
Priority date	Apr 28, 2022
Publication date	Dec 23, 2025
Grant date	Dec 23, 2025

Abstract

A method for preparing an ablation-resistant high-entropy carbide-high-entropy diboride-silicon carbide (SiC) multiphase ceramic, including: (S 1 ) mixing a transition metal oxide mixed powder, nano carbon black and a silicon hexaboride (SiB 6 ) powder to obtain a precursor powder; and (S 2 ) subjecting the precursor powder to pressureless sintering to obtain the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic with a relative density of 96% or more.

First claim

What is claimed is:

1 . A method for preparing an ablation-resistant high-entropy carbide-high-entropy diboride-silicon carbide (SiC) multiphase ceramic, comprising:
(S 1 ) mixing a transition metal oxide mixed powder, nano carbon black and a silicon hexaboride (SiB 6 ) powder to obtain a precursor powder; and (S 2 ) subjecting the precursor powder to pressureless sintering to obtain the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic; wherein a relative density of the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic is 96% or more; and wherein the transition metal oxide mixed powder comprises hafnium oxide (HfO 2 ), zirconium dioxide (ZrO 2 ), tantalum pentoxide (Ta 2 O 5 ), niobium oxide (Nb 2 O 5 ) and titanium dioxide (TiO 2 ) in a molar ratio of 2:2:1:1:2; and the pressureless sintering is performed in a stepwise manner through the following temperature program: rising from room temperature to 1900-2100° C. at a rate of 10-50° C./min; 1900-2100° C. for 5-30 min; decreasing to 1600-1900° C. at a rate of 50-100° C./min; 1600-1900° C. for 1-8 h; and decreasing to room temperature at a rate of 10-50° C./min; wherein a vacuum degree of the pressureless sintering is controlled at 0.001-0.05 Pa.

2 . The method of claim 1 , wherein a molar ratio of transition metal atoms of the transition metal oxide mixed powder to the nano carbon black to the SiB 6 powder is (1-20):(1-64):(0-8), and a molar content of the SiB 6 powder is greater than zero.

3 . The method of claim 1 , wherein a particle size of the transition metal oxide mixed powder is 100 nm; a particle size of the nano carbon black is 50 nm; and a particle size of the SiB 6 powder is 3-8 μm.

4 . The method of claim 1 , wherein step (S 1 ) comprises:
(S 1 - 1 ) subjecting HfO 2 , ZrO 2 , Ta 2 O 5 , Nb 2 O 5 and TiO 2 to ball milling and drying to obtain the transition metal oxide mixed powder; and (S 1 - 2 ) subjecting the transition metal oxide mixed powder, the nano carbon black and the SiB 6 powder to ball milling and drying to obtain the precursor powder.

5 . The method of claim 4 , wherein in step (S 1 - 1 ), the ball milling is performed in isopropyl alcohol at 200-600 rpm for 8-60 h, and a ratio of a total weight of HfO 2 , ZrO 2 , Ta 2 O 5 , Nb 2 O 5 and TiO 2 to a weight of balls is 1:(10-20); and
In step (S 1 - 2 ), the ball milling is performed in isopropyl alcohol at 200-600 rpm for 8-60 h, and a ratio of a total weight of the transition metal oxide mixed powder, the nano carbon black and the SiB 6 powder to a weight of balls is 1:(10-20).

6 . The method of claim 1 , wherein before the pressureless sintering, the precursor powder is pre-pressed into a cylindrical blank by cold isostatic pressing.

Assignees

• Univ Zhejiang Normal

Inventors

• Hao Wei
• Chen Xinyue
• Zhou Chunni
• Qin Xiaoxian
• Wang Dongyun

Classifications

• C04B2235/96

  Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance · CPC title

• C04B2235/77

  Density · CPC title

• C04B2235/6581

  Total pressure below 1 atmosphere, e.g. vacuum · CPC title

• C04B2235/6567

  Treatment time · CPC title

• C04B2235/6565

  Cooling rate · CPC title