| With the development of advanced technology, the performance of the complex and poor working environment, which made more stringent requirements of the bearing, the traditional bearing which is made by the ball and lubricating oil lubrication is not suitable for these working environments such as high speed, heavy load, high temperature and strong chemical corrosion and other special environment. Starting from the friction mechanism of self-lubrication material, to produce the self-lubricating bearing can be applied to civilian aircraft, automobiles, heavy machinery and other more special working environment, has a important significance to promote the development of liner composites.In this paper, taking the Polytetrafluoroethylene(PTFE) yarn, Aramid 1313(Nomex),PTFE/ Nomex yarn, plied yarn as raw materials, weaving a spacer fabric woven, after the surface treatment, sizing processing, curing processing preparation to produce into lining composite materials. Adopting the multi-functional friction and wear testing machine to test the friction coefficient and the wear rate, to study the influence of fabric structure on properties of friction properties, these are the main research contents and results:1) In the same conditions of test materials and test conditions, with the warp and weft yarn density increased, the friction coefficient and the wear rate of lining composite material reduced gradually, this showed that with warp and weft density increased within the range of weaving, self-lubricating property of lining composite materials would be better, wear resistance would be improved obviously.2) By the experiments of plain and broken crow twill, the lining composite material which made by PTFE had a good lubrication performance and bad wear performance, PTFE was not suitable for warp, used Nomex/PTFE plied yarn as warp, Nomex as weft, the friction coefficient of lining composite material increased from 0.0983 to 0.1257, the wear rate reduced substantially from 0.096 mm to 0.04 mm, this manifested extremely excellent lubrication performance and wear resistance.3) By the experiments of broken crow twill, plain, 1/3 twill, 2/2 twill, 8 pieces of 3 fly satin and double-large weave, the lining composite material of 1/3 twill had the lowest friction coefficient reached 0.1026, the amount of wear was 0.024mm; 8 pieces of 3 fly satin’s friction coefficient and the wear were 0.1311 mm and 0.052 mm. By the experiments of damp heat test to study tolerance of hot and humid environment, then found that moisture content of 1/3 twill was minimal, the quality was increased from 1.0444 g to 1.0456 g, the absorption rate was fast, That had strong resistance to hot and humid climate performance. This research focused on the the effect of organization structure on friction performance.4) By the contrast experiments of pure PTFE, Nomex material and blank experiment, the effect of transfer film lubrication of PTFE material on both lubrication performance and wear performance, it showed that: the formation of clearly crescent polishing scratch in the Nomex area proofed that the PTFE material would indeed form transfer film lubrication in the friction process, then transfer film lubrication transferred to the Nomex material would reduce the degree of wear. Using the scanning electron microscopy(SEM) to analysis the friction area, and to study the friction and wear mechanism of lining composite materials, discovered that PTFE material didn’t have obvious fiber breakage and single fiber because of friction, wear regions exhibited nearly planar state, and on both sides of the wear scar was squeezed out of the deposits, suggesting that PTFE material occurred creep and slip because of friction shear stress. The layered PTFE material appeared on the Nomex material in the Nomex region, which further indicated that transfer film of PTFE attached to the surface of Nomex fiber. Comparison of different wear area of Nomex material, which found that when transfer film of PTFE attached to the surface of Nomex fiber, the wear significantly reduced, surfacing, also demonstrated that the presence of PTFE transfer film is beneficial to reduce the degree of wear. |
PDF Full Text Request