Abstract: Disclosed is a carbon fiber preform, a preparation method therefor and a preparation method for carbon/carbon composites, falling within the technical field of composites. The carbon fiber preform provided by the present disclosure includes a plurality of stacked carbon fiber cloths and prestressed layers arranged between every two of adjacent carbon fiber cloths, the prestressed layer including a boron-containing phenol-formaldehyde resin coating and carbon fiber bundles distributed within the boron-containing phenol-formaldehyde resin coating. In the present disclosure, the prestressed layers are formed by adding the carbon fiber bundles and a boron-containing phenol-formaldehyde resin precursor to a two dimensional (2D) stacked preform, thereby counteracting internal stresses during carbonization and obtaining a carbon/carbon composite having higher strength and being less prone to cracking.

Abstract: Disclosed is a carbon fiber preform, a preparation method therefor and a preparation method for carbon/carbon composites, falling within the technical field of composites. The carbon fiber preform provided by the present disclosure includes a plurality of stacked carbon fiber cloths and prestressed layers arranged between every two of adjacent carbon fiber cloths, the prestressed layer including a boron-containing phenol-formaldehyde resin coating and carbon fiber bundles distributed within the boron-containing phenol-formaldehyde resin coating. In the present disclosure, the prestressed layers are formed by adding the carbon fiber bundles and a boron-containing phenol-formaldehyde resin precursor to a two dimensional (2D) stacked preform, thereby counteracting internal stresses during carbonization and obtaining a carbon/carbon composite having higher strength and being less prone to cracking.