Nano aluminum nitride powder has high specific surface area, high hardness, high thermal conductivity, high insulation and other characteristics, belongs to diamond-like nitride, can be stable to 2200℃, high strength at room temperature, good compatibility with the matrix interface, can improve the thermal conductivity and dielectric properties, mechanical properties and wear resistance of the composite.
PTFE, commonly known as “plastic king”, has a linear molecular chain structure and is a non-polar polymer, with good chemical corrosion resistance, high and low temperature resistance, minimal friction factor and excellent dielectric properties. However, its disadvantages such as poor wear resistance, poor creep resistance and large bearing deformation limit its application scope. In order to improve the comprehensive performance of PTFE, some researchers have been working on the modification of PTFE to expand its application in various fields. Among them, filling inorganic powder is a simple and effective method to improve the performance of PTFE. In addition to the commonly used graphite, glass fiber, carbon fiber, molybdenum disulfide and other modified fillers of PTFE, PTFE can also be filled with nano aluminum nitride powder to obtain good results.
1. Nano aluminum nitride powder added in PTFE matrix ACTS as nucleating agent. The crystallinity of PTFE/ nano-aln composite increases first and then decreases with the increase of nano aluminum nitride content.
2. The addition of nano aluminum nitride powder improves the comprehensive mechanical properties of the material. When the content of micro aluminum nitride powder is 2%, a large value appears.
3. Adding nano aluminum nitride powder increases the friction factor and decreases the wear volume of PTFE/ nano-aln composite. When the content of nano aluminum nitride powder is 4%, the wear volume is only 1.4% of pure PTFE.
4. Pure PTFE shows typical adhesive wear characteristics. When the content of nano aluminum nitride powder is low, the wear mechanism of PTFE/ nano-aln composite material is mainly characterized by different degrees of adhesive wear and abrasive wear characteristics, improving wear resistance.