Issue 12/2022 - Ultra-high temperature resistant lightweight carbon-based composite successfully prepared

Recently, the thermal structure composite materials team of the Institute of Metal Research of the Chinese Academy of Sciences used high-pressure assisted curing-atmospheric drying technology to prepare ultra-high temperature heat insulation-bearing integrated lightweight carbon matrix composites
through matrix microstructure control, fiber-matrix synergistic shrinkage and in-situ interface reaction.

Due to their excellent thermal stability and thermal insulation, carbon aerogels (CAs) are expected to be a breakthrough solution
for the design of a new generation of advanced ultra-high temperature lightweight thermal protection systems.
In recent years, the research team has successively developed two CAs preparation technologies of sol gel-aqueous atmospheric drying and high-pressure assisted curing-atmospheric drying, and designed an ultra-low density carbon-organic hybrid fiber reinforcement, giving it excellent superelasticity
.
The material enables efficient, low-cost preparation and has properties
such as low density, low thermal conductivity and high compressive strength.

On this basis, the team used industrial phenolic resin as the precursor, high boiling point alcohols as pore forming agent and supplemented by high-pressure curing to achieve the improvement of the intrinsic strength of the skeleton, and at the same time used phenolic fibers with good matching with the precursor organic aerogel as the reinforcer, through the fiber/matrix interface in situ reaction, the synergistic shrinkage of the matrix and the fiber and the strong chemical combination of the fiber/matrix interface during the carbonization process were realized, and finally a large-size, crack-free carbon fiber reinforced CAs composite was
obtained 。 The density of the material is 0.
6 g/cm³, its compressive strength and in-plane shear strength can reach 80 MPa and 20 MPa, respectively, and the thermal conductivity is only 0.
32W/(m· K), its specific compressive strength is higher than that of aerogel materials and carbon foams
reported in the known literature.
The material also has higher mechanical strength and exhibits excellent ultra-high temperature resistance, heat insulation and load-bearing properties
.

As a rigid thermal insulation material, the material has been installed and used in many advanced engines, providing key technical support
for model development.