Polytetrafluoroethylene (PTFE) composite material and preparation method thereof

Abstract

The invention relates to a polytetrafluoroethylene (PTFE) composite material and a preparation method thereof. The composite material comprises the following components by mass percentage: 5 to 20% of polyether ether ketone (PEEK) powder and 78-94.5% of PTFE powder of which the average particle sizes are less than or equal to 100 microns, and 0.5-2.0% of nano-diamond powder of which the average particle size is less than or equal to 20 nm. The preparation method utilizes the mass percentage of the composite material of the invention and the following processes: 1. using a stirring ball mill to disperse the nano-diamond powder and dispersing agent polyvinylpyrrolidone (PVP) in ethanol medium, milling the mixture into zirconia balls being 0.2-1.0mm in the condition of rotating speed being 500-600 r/min and stirring time being 2-5h, screening the zirconia balls after even dispersion to obtain nano-diamond dispersal liquid; and the mass ratio of nano-diamond powder and dispersing agent being 10:1; 2. adding PEEK powder and PTFE powder into nano-diamond dispersal liquid and then stirring for 1-3h, drying the stirred mixture at a temperature of 70-90 DEG C after even mixing to obtain mixed powder; 3. cold press molding; and 4. high-temperature sintering to obtain the PTFE composite material.

Description

Technical field: [0001] The invention relates to a composite material technology, in particular to a polytetrafluoroethylene composite material with high wear resistance filled with anti-wear reinforcing components and a preparation method thereof. Background technique: [0002] Polymer-based antifriction composites are being used more and more in the field of mechanical engineering as a substitute for metal materials. Polytetrafluoroethylene (PTFE) has a low coefficient of friction, good self-lubrication and excellent corrosion resistance, and is an ideal friction-reducing and self-lubricating material. However, due to its extremely low surface energy and poor wear resistance, PTFE is generally used in the form of composite materials in the field of mechanical engineering. At present, glass fiber, carbon fiber, graphite, molybdenum disulfide, non-ferrous metal powder and other inorganic reinforcing components are commonly used to modify PTFE to improve its strength, wear r...

AI Technical Summary

Problems solved by technology

However, these inorganic fillers have poor compatibility with PTFE, which will increase the friction coefficient of the composite material and cause damage to the friction surface, thus restricting the improvement of the quality and wide application of PTFE composite materials.

Patent literature (CN1473865A) discloses a polytetrafluoroethylene composite material reinforced with nano-diamonds, which can improve the wear resistance of the composite material, but the addition of nano-diamonds in the composite material is relatively high, and the preferred solution also needs to add metal and rare earth, so the cost of the composite material is high, which is not conducive to the promotion of use; especially in its preparation method, nano-diamonds only use grinding methods, it is difficult to make them uniformly dispersed, and they are easy to agglomerate to form micron-sized secondary aggregates , affecting the performance of nano-diamonds, which is not conducive to the improvement of the performance of composite materials