Study On A Wear-Resistant Composite Coating With Bionic Non-Smooth Surface

Abrasive wear is one of main reasons that brings about the soil-engaging components of terrain machines such as mining, engineering, agricultural machines and so on to lose efficacy. In addition to developing new type wear-resistant materials, adding lubricant materials and designing rationally for the structures, surface hardening technologies for the soil-engaging components of terrain machines are the significant methods that can improve quality and wear resistance of the components and prolong their service life. Up till now, the surface hardening technologies in common use are a variety of treatment technologies including chemistry, physics, laser and electron beam and bead welding, spraying, depositing, plating and so on. The whole surfaces are treated using technologies usually and the costs are higher, but the thickness of hardening coating is thinner and worn quickly on an extended term of service that loses their protective coating and reduces effectiveness of the machine components in using. Moreover, raising surface hardness of engineering materials is limited. Consequently, developing new-type wear-resistant materials and mechanisms would improve service life of the soil-engaging components of terrain machines effectively. Traditional concepts seek surface lubricity as necessary conditions that improve wear resistance of the machine components.Bionic Research results show that non-smooth surface can reduce adhesion and resistance of materials and improve wear-resistant performance that give birth to designing idea of the wear-resistant composite coating with bionic non-smooth surface. Based statistical analysis on geometrical morphologies of most soil animal body surface, a mathematic description formula is set up for the non-smooth surface of typical soil animal body. Limits of numerical value of mathematic description formula are ascertained and the mathematic model is set up using arithmetic operation and genetic algorithm. Aim of this work offer theoretical bases to study composite coating with bionic non-smooth surface. Brazing reinforced particles to steel surface using filler metals, a composite coating with bionic non-smooth surface in thickness from tens microns to tens millimeter is formed. The brazing technology is used to manufacture composite coating with bionic non-smooth surface that possesses the characteristics of simple technics, convenient operation, lower cost and credible performance.Results show that the brazing methods, flux, wettability of filler metal to reinforced particles and to steel surface, size and weight percent of reinforced particles have significant influences on the molding, porosity, density and wear resistance of the composite coating with bionic non-smooth surface. The wear resistance of the composite coating with bionic non-smooth surface using high frequency induce brazing exceed that of furnace brazing. Porosity and density represents the close-grained measurement, compactness and wear resistance of the composite coating directly. The Cu-Zn filler metal (BCu60Zn) has lower price and melting point, good anti-erosion and wettability and filling up vacancy to reinforced particles and steel surface. BCu60Zn filler metal is processed to powder in granularity of 175~246μm and mixed with carbide tungsten and flux in weight percent of 50 and 1-3, respectively. A composite coating with bionic non-smooth surface is formed using high frequency induce brazing on the steel surface. The structures of composite coating are compact, its porosity is lower and density is high. Under the condition of two bodies abrasive-wear, the wear resistance of composite coating with bionic non-smooth surface is 11.9 and 4.7 times as much as that of 45# steel (quench-hardening) and high chrome cast iron respectively.The influences of service conditions on the wear resistance of the composite coating with bionic non-smooth surface are studied. The results show, with increasing the loading, the wearing capacity of the composite coating is greatly enhanced when load...