Silicon nitride-based self-lubricating composite material

Abstract

The invention discloses a silicon nitride-based self-lubricating composite material. The silicon nitride-based self-lubricating composite material is prepared from the following chemical components in percentage by volume: 8 to 12 percent of OLC (Onion-like carbon), 8 to 12 percent of TiN0.3 and the balance of alpha-Si3N4. A preparation method of the self-lubricating material comprises the following steps: putting the TiN0.3, the OLC and the alpha-Si3N4 into a planetary ball mill, wherein a ratio of grinding media to material is 10 to 1, and the rotating speed is 300 to 350r / min; clockwise rotating for 30 minutes, stopping for 15 minutes, counterclockwise rotating for 30 minutes, stopping for 15 minutes, and circulating for four cycles; filling a die with mixed powder, maintaining the pressure of 20 to 40MPa for 10s, drying for 8 hours, and then carrying out high-temperature and high-pressure sintering, wherein the pressure is 5GPa; heating to 1480 to 1520 DEG C, keeping the temperature for 14 to 16 minutes, and furnace cooling; grinding a prepared blank, and carrying out deburring treatment to obtain the Si3N4-based self-lubricating composite material. The self-lubricating composite material prepared by the preparation method disclosed by the invention has the advantages of high hardness, high thermal shock resistance, wear resistance, corrosion resistance and the like; the self-lubricating composite material also has higher toughness, and is suitable for being applied to a device material between lubrication-free interfaces at higher temperature.

Description

technical field [0001] The invention belongs to the technical field of materials, in particular to a self-lubricating composite material. Background technique [0002] Ordinary Si 3 N 4 The base material has a series of excellent properties such as high strength and high hardness, thermal shock resistance, spalling fatigue wear, wear resistance, acid and alkali corrosion resistance, but has disadvantages such as low toughness, difficult sintering, and high dry friction coefficient. In order to improve Si 3 N 4 In the case of poor toughness and difficult sintering of ceramics, Zou Bin used nano-TiN powder as the second phase additive to prepare silicon nitride-based nanocomposite ceramic cutting tools. The fracture toughness, Vickers hardness and bending strength were 9.1MPa m 1 / 2 , 15.47GPa and 1079.8MPa, and it is proposed that nano-TiN can reduce the sintering temperature, improve the sintering activity of the powder, and improve the mechanical properties and mechanica...

AI Technical Summary

Problems solved by technology

[0003] Today, with the rapid development of aerospace technology and space technology, most of the working parts of aerospace equipment are in extreme environments such as ultra-high and ultra-low temperature, vacuum, high speed, and corrosive media. Under such extreme conditions, conventional lubricants are very easy to evaporate, causing The lubrication mechanism fails; plastic-based solid self-lubricating composite materials are only suitable for low-speed, low-load, and low-temperature conditions; metal-based self-lubricating composite materials cannot cope with extreme conditions such as high and low temperature heavy loads, radiation, special medium corrosion, and thermal shock; therefore, It is of practical significance to study a self-lubricating composite material suitable for extreme working conditions in space as a sliding bearing material