Study On Aluminium-Znic Alloy Bearing Material

There are three kinds form of ideal anti-friction and wear resistant organization. One is the soft metal matrix with hard particles dispersed, such as traditional Babbitt. Another is a hard metal matrix with distribution of the soft particles, such as Al20SnCu copper-lead alloy. One is the metal matrix with the distribution of soft particles and hard particles at the same time, such as aluminum-tin-silicon bearing alloy and aluminum-lead-silicon bearing alloy.The good tribological properties of Al-Zn alloy mainly related to multiphase structure of the aluminum and zinc oxide on the friction surface. Hardness of aluminum oxide is high, with good carrying capacity, and zinc oxide is soft, its hexagonal structure has allowed it to exist as a lubricant, it is similar to the role of adding lead to aluminum alloy.Adding silicon can improve the wear resistance and anti fatigue and anti bonding of bearing materials, reduce the linear expansion coefficient. Silicon content, the distribution of silicon particles, silicon particle size can influence the tribological properties of the alloy.Copper as a strengthening phase adding to the alloy, solid solubilization with aluminum and generate compound. It can improve the mechanical properties and anti fatigue of the alloy. If the cooper content is too high, the cooper and the aluminum matrix can generate a hard and brittle middle phase, CuAl 2 , it can reduce the deformation properties of the alloy, increases the tendency of cracking in rolling process, reduce the cast performance of the alloy, in addition, the cooper can reduce the corrosion resistance and plasticity.This issue takes Al-Zn alloy as a reference object, by adjusting the alloy composition, in particular cancel the element of lead, study on the mechanical and wear behavior of the alloy, explore the appropriate alloy composition.According to the orthogonal design, the component of the alloy has been confirmed, casting aluminum alloy specimen under 760 degrees, studying on mechanical properties, alloying elements was found to be controlled in the range of that, Zn 4%-5%,Si 1%-2%,Cu 2%-3%.Through the wear test, study on tribological properties of the alloy, started from the wear, after 180 minutes, it reached the stable wear stage, to find the wear rate of the stage.Considering the performance requirements of bearing alloy in total, calculate a optimization index with tensile strength, plastic indicators, Brinell hardness, and average wear rate. After BP network training, finally, technology has been optimized for: Zn4%,Si1%,Cu3%,holding time 80 minutes. The corresponding performance index is: average wear rate: 1.265×10^-4;Brinell hardness: 58.68HB;plastic indicators: 19.29%;tensile strength: 159.66MPa...