A zirconium diboride-based composite material toughened by colloid-dispersed chopped carbon fibers and its preparation method

Abstract

The invention discloses a zirconium diboride-based composite material toughened by colloid-dispersed chopped carbon fibers and a preparation method thereof and belongs to the technical field of ultrahigh-temperature ceramic-based composite materials. The zirconium diboride-based composite material is prepared from the raw materials including, by mass, 1-3 parts of the chopped carbon fibers, 15-25 parts of nano zirconium diboride powder, 1-3 parts of nano silicon carbide powder, 1-5 parts of phenolic resin, 0.1-0.5 parts of polyethyleneimine, and 60-100 parts of anhydrous ethanol. In the invention, the phenolic resin and the polyethyleneimine are subjected to a crosslinking reaction, wherein the short carbon fibers are uniformly dispersed in the colloid, thereby overcoming a problem of abrasion of the fibers during conventional ball-milling material blending. Through the colloid dispersion method, a high-temperature protective layer is formed on the surface of the carbon fibers, and further degradation rate during high-temperature sintering of the carbon fibers is reduced, interface bonding among fiber substrates is weakened, and debonding, bridge connection and pulling-out of the fibers are promoted. The zirconium diboride-based composite material has high compactness, high strength and high toughness.

Description

technical field [0001] The invention belongs to the technical field of ultra-high temperature ceramic-based composite materials, and relates to a ceramic-based composite material with chopped carbon fiber as a toughening phase and zirconium diboride as a matrix phase and a preparation method thereof, which overcomes the problems caused by traditional ball milling dispersion methods. fiber abrasion problem. Background technique [0002] Zirconium diboride (ZrB 2 ) has a high melting point (3200°C), high strength (500MPa), high hardness (23GPa), and excellent oxidation resistance and ablation resistance, making it one of the most promising ultra-high temperature structural materials. ZrB 2 It has broad application prospects in metallurgy, nuclear power generation, aerospace and other fields, and is expected to be used in key components of hypersonic aircraft thermal protection, such as: nose cone, wing leading edge, engine combustion chamber and nozzle. However, ZrB 2 The ...

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Problems solved by technology

[0012] (3) During the ball milling process, the fiber and the matrix powder have to experience high-speed friction for a long time, which will increase the reactivity between the fiber and the matrix, making it easier for the fiber and the matrix to undergo chemical reactions during high-temperature sintering. This leads to higher interfacial bonding, which is not conducive to toughening mechanisms such as fiber pull-out

[0013] Therefore, both in Documents 1 and 2, carbon fiber wear and reaction phenomena can be found, and the length of fiber extraction is also very limited, which seriously limits the toughening effect of chopped carbon fiber

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