The Research On Mechanical And Friction And Wear Properties Of Nano-infared Ceramic Powders/UHMWPE Composites

Far infrared nano ceramic powder is a powder material that can emit far infrared,which has some far-infrared thermal effects,and nano-powders with a smaller particle size,high surface area,so that it has different structural effects from common materials.The study shows that putting the nano-powders as additives to UHMWPE,that can significantly improve the tribological properties and mechanical property of composite.According to the excellent properties of nanometer far-infrared ceramic powder,we guess that it can improve the mechanical and wear resistance of UHMWPE.In order to study the far infrared nano ceramic powder as additives to effect of properties of UHMWPE,surface modificate far infrared nano-ceramic powder first,through orthogonal test,the optimum conditions of surface modification were selected,namely,hydrolysis time,temperature,pH and the amount of modifier;The dispersion properties of the optimized nano powders were characterized by IR,TGA and TEM.The modified particles were added to UHMWPE,and the composite materials were heat treatment,analysis of the crystallization properties(gel content,crystallinity),hardness and tensile properties of the composite,research the influence of content and heat treatment on the crystallization behavior of UHMWPE;Measuring the the friction coefficient and wear properties under different conditions(content of nano far-infrared ceramic powder,load,sliding speed,lubrication medium),study the friction and wear mechanism of composite,the friction and wear mechanism was studied.In the nano powder surface modification experiments,The best modifier KH570 was selected by the determination of lipophilic degree,The orthogonal test was used to determine the optimum dosage of 4%,modified time is 45 min,modified temperature is 68 ?,pH value of hydrolysis solution is 4.By means of Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis and transmission electron microscopy(TEM),the dispersion stability of the particles was confirmed,and new chemical bonds were produced during the surface modification.The effects of particle addition amount and heat treatment on the crystallization properties,surface hardness and tensile properties of UHMWPE composites were investigated by gel rate and mechanical tests.Results show that: The tensile strength of UHMWPE composites increased obviously and the elongation at break decreased with the addition of nano ceramic powders;the surface hardness of the composites increases with the increase of filler;When the amount of nano far-infrared ceramic powder was 3%,the crystallinity of the composite was the best;after heat treatment,the properties of the composites were improved to some extent.In the friction and wear test,under dry friction condition,under the same load and linear velocity,the friction coefficient of the composites increases with the increase of the mass fraction of nano far-infrared powder.Under the same mass fraction and linear velocity of the far infrared ceramic powder,the friction coefficient decreases first and then increases with the increase of load.Under the mass fraction and the load of the same nanometer far-infrared ceramic powder,the friction coefficient of composites decreases with the increase of linear velocity.Under the same load and linear speed,the wear rate of the composites is the lowest when the nano far-infrared ceramic powder is 3%,the lowest wear rate of composites.Under the same condition,the wear rate increases with the increase of load and linear speed.Under the condition of water lubrication,the friction and wear of the friction pair of the composite material is obvious.Compared with the dry friction,the water lubrication shortens the time of the friction pair,and the stable friction coefficient is half that of the original.Under water lubrication,Within the 10~60N range,The friction coefficient of UHMWPE composites increases firstly and then decreases with the increase of load;Under the same loading condition,the increase of wire speed can reduce the friction coefficient of the composites,Under the same working condition,the increase of load and linear speed can increase the wear rate of composites.