Multiple Alloying Research Of Low Tin Aluminum Bearing Alloy

One of the aluminum base bearing alloy as the sliding bearing material widely used in machinery manufacturing and other industries. But as the modern engine be developed towards the direction of high speed, high pressure and overload, put forward higher requirements on the performance of the aluminum alloy. Low tin alloy not only has higher bearing capacity and fatigue resistance, corrosion resistance, etc, but also its quality is light, low cost, can save valuable non-ferrous metals,it has very important application value. This article mainly researches the tin content less than 5% of the aluminum base bearing alloy, proposed by multiple alloying and refining treatment, ultrasonic treatment and solid solution treatment to research the change and the law of the aluminum alloy solidification structure and mechanical properties as well as the friction and wear performance. The main conclusions are as follows:(1) Studied the influence on the microstructure and hardness of Al-Si-Sn-Cu alloy. With the quantity of Sn, Cu elements. Results showed that with the increase of the amount of Sn, β(Sn) phase in the alloy tissue increased, reticulate distribution, refining grain obviously, but the hardness of alloy is decreased. When the addition of Cu content increased, alloy group without obvious changes, but due to the solid solution strengthening of Cu and Al2Cu dispersion strengthening effect, the hardness of alloy be increased with the increase of Cu.(2) Studied the influence on the microstructure and hardness after the refining treatment with Al-5Ti-1B and ultrasonic treatment of Al-Si-Sn-Cu alloy. Results showed that after refining processing,a(Al) appears obvious refinement, eutectic Si phase has also been refinement by the thick plate strip into fibrous structure, the grain shape becomes rounded, and uniform distribution, the hardness also must be improved. After ultrasonic treatment,the grain shape becomes rounded, and uniform distribution,too. As the increase of processing time, import, frequency, duty cycle, the refining effect more apparent.(3) Studied the influence on the microstructure and hardness of Al-Sn-Cu alloy with the quantity of Sn, Cu elements.The results showed that with the increase of the content of Sn, dense mesh boundary changes, grain refinement, spherical Sn phased at grain boundary, the hardness of alloy decrease. And with the increase of Cu content, due to the effect of solid solution strengthening of the Cu and Al2Cu dispersion strengthening effect, significantly improve the hardness of alloy.(4) Studed the influence on the microstructure and hardness of Al-Sn-Cu alloy with the solid solution and aging treatment. The results showed that after solid solution and aging treatment, Al-Sn-Cu alloy grain growth,β(Sn) in the tissues be fused and spherized, and uniform distribution. The small and diffuse Al2Cu be precipitated on the a(Al) solid solution, make the alloy substrate gets greatly improved.(5) Studied the influence of friction and wear performance with the quantity of Sn,Cu elements of Al-Sn-Cu alloy. The results showed that the wear mechanism of Al-Sn-Cu alloy mainly adhesion and furrows. When the Sn content is low, enhance the wear resistance of alloy, but make the friction coefficient of alloy increases, make the alloy anti-friction performance to reduce. Along with the increase of the content of Cu, the hardness of Al-Sn-Cu alloy wear resistance increased.