Reciprocating friction and wear performances of nanometer sized‐TiO₂ filled epoxy composites

Abstract

Nanometer-sized particles, for example, TiO 2 , have gradually gained the attention to improve the mechanical and tribological properties of epoxy composite coatings. In the present paper, TiO 2 with the size of 300 nm was applied to improve the reciprocating friction and wear performances of an epoxy composite. The effects of TiO 2 content and sample preparation methods on the mechanical and tribological performances were investigated experimentally. It was found that the optimal mixture ratio of TiO 2 was 4 wt%, and the tensile strength of composite increased by up to 30% compared with the control sample. The TiO 2 nanoparticles were treated with polyvinylpyrrolidone (PVP) and then mixed into epoxy resin with three-roll mill grinding technique. The PVP molecules could surround a single TiO 2 to form super-monomer, which produced repulsive force to aim to disperse nanoparticles, and the three-roll mill grinding could utilize the compression of axis surfaces and friction at different speeds to reduce the size of agglomerations of more than 5 microns. The results showed that the PVP molecules treatment could improve tensile strength and modulus, and three-roll mill grinding technique could enhance the elongation at break. In addition, the reciprocating wear rate and frictional coefficient of the epoxy composite plates also were reduced remarkably owing to the pretreatment of TiO 2 particles, for example, and the frictional coefficient of epoxy composite decreased from 0.09 to 0.04 for the optimal ratio of TiO 2 , and special wear rate also decreased by 87.5% compared with the control sample. This was because the TiO 2 nanoparticles acted as the stress transfer medium and could undertake part of loading to relieve stress directly into the epoxy matrix. There was a thin transfer film in which the particles acted as a membrane skeleton to avoid matrix further being torn. Because of the hardness and nanoeffect of particles, TiO 2 could fill the defects in the wear interface to form a protective film and improve surface fatigue resistance property. The more uniform dispersion of TiO 2 particles brought about the obvious improvement of wear resistance of composites.

Mechanical property degradation of X80 pipeline steel due to microbiologically influenced corrosion caused by Desulfovibrio vulgaris

“…It is the highest point of the Y -axis in Figure 11 . The ultimate strain (elongation at break) demonstrates the ability of a material to resist shape change before finally breaking ( Tian et al, 2021 ). It is the largest value of the X -axis (strain) in Figure 11 ( Sluzalec, 1992 ).…”

Hygrothermal Aging Characteristics of Silicone-Modified Aging-Resistant Epoxy Resin Insulating Material

“…From the physical point of view, the cracks may grow when free water molecules inside the pores change into vapor, causing a rise of internal stress inside the pores. It has been reported elsewhere that the addition of silicone materials can improve the mechanical properties of materials [ 21 ], and the addition of diphenylsilanediol may improve the ability of the material to withstand internal stress by transferring internal stress and increasing the molecules’ flexibility [ 22 , 23 ]; this means that more energy may be needed to cause stress concentration that is severe enough to break the material, thus inhibiting the generation and development of cracks and pores. These observations prove the assumption in Section 3.2 that the size of cracks and holes may play an important role in the changes of PDIV.…”

Effect of the Addition of Thermoplastic Resin and Composite on Mechanical and Thermal Properties of Epoxy Resin

“…On the other hand, the mechanical properties and durability of epoxy resin can be further improved by adding some functional nanoparticles to epoxy resin. Tian et al [ 25 ] studied experimentally the effects of titania content and sample preparation methods on the mechanical performances of epoxy. They found that the tensile strength of epoxy increased by up to 30% compared with the control for the optimal mixture ratio (4%) of titania.…”