Study On The Tribological Behaviors Of Several Hybrid Fillers Reinforced Epoxy Resin Composites

Friction and wear are two main factors leading to the failure of mechanical components and energy waste.Owing to good mechanical properties,low shrinkage rate and excellent chemical stability,Epoxy resin（EP）is broadly applicated in electronics,electrical,aerospace,automotive and other fields.Whereas,the high brittleness and poor thermal performance of the pure EP affect its tribological properties badly.Thus,it is an effective strategy to adding diverse reinforced fillers into the EP matrix to improve the anti-wear performance of EP composites.However,with the progress of science and technology,single and typical reinforced filler cannot meet the further requirements for the tribological properties of epoxy matrix composites.At the same time,the limited performance of traditional fillers,the poor dispersion of reinforced fillers,and the unexpected thermal conductivity of EP matrix restrict the further application of EP composites in friction field.Therefore,in this thesis,a new MXene-based hybrid filler,an RGO-based hybrid aerogel and a bacterial cellulose derived carbon nanofiber aerogel were successfully designed and obtained,and then they were applied to improve the tribological performance of epoxy resin matrix.The main research contents are shown as follows:（1）Multi-layer Ti₃C₂ MXene with according-like morphology was obtained by HF etching.Then the silver nanoparticles（Ag NPs）were grown in-situ on the surface of MXene to prepare the MXene@Ag hybrids.Research results shown that the MXene@Ag hybrids could significantly improve the thermal properties,mechanical performance and tribological properties of EP matrix.In addition,the anti-wear mechanism of the EP composites was analyzed through the morphologies of the worn surface,abrasive debris and tribo-films.（2）RGO/Si₃N₄ hybrid aerogel（GSiA）with three-dimensional porous structure was prepared by hydrothermal reduction method;Among them,the surface of Si₃N₄whiskers was coated by PDA-PEI copolymer to improve the dispersion of Si₃N₄@PDA-PEI whiskers in EP matrix.Finally,the GSiA were added to EP matrix to prepare the GSiA-EP composites.The experimental results showed that RGO sheets and Si₃N₄@PDA-PEI whiskers constructed a relatively continuous thermal network in the EP matrix.Compared to the pure EP,the thermal conductivity of GSiA₁-EP was improved significantly.And the hardness of GSiA₁-EP was also increased by 48%;Besides,the friction coefficient and wear rate of GSiA₁-EP were decreased by 83.7%and 35.8%,respectively.（3）The MXene@MoS₂/Bacterial cellulose derived carbon nanofiber hybrid aerogel（MMoCA）with well aligned lamellar structure was prepared by freeze-drying process and carbonization treatment.The research results showed that the MXene@MoS₂ attached to nanofiber surface presented good dispersion inside the aerogel.And the MMoCA endowed epoxy resin matrix with the excellent thermal conductivity,toughness and friction performance.It was attributed to the rich active sites and rough structure of MXene@MoS₂ and the well-ordered thermal diffusion framework of MMoCA.Moreover,the structure of tribofilms was characterized by scanning electron microscope and transmission electron microscope,and the friction-induced evolution and formation of high-quality transfer films of MMoCA-EP were explored systematically.