Study On In-Situ Particle-Reinforced Al-10Sn Matrix Anti-Friction Composites

It is an important object for material researcher to develop a new bearing material with promising tribological properties, low cost and non-pollution. Based on the thermodynamics analysis of the Al-KBF₄-K₂TiF₆-NaAlF₆ reaction system, a new aluminum matrix antifriction material, namely, in-situ TiB₂ particle-reinforced Al-10Sn matrix anti-friction composites was fabricated by the Mixed Salt Reaction synthesis process in this thesis. The solidification phase and microstructure of the composites were analyzed by XRD and SEM. The hardness of the composites was measured with universal material hardness tester using Vickers indenter, and the sliding friction and wear characteristics of the composites and matrix alloys were investigated with friction-wear tester under diverse conditions. The cold-rolling recrystalization of the composites and matrix alloys was studied systemically.The results were summarized as follow. (1) The investigation showed that there were α-Al, β-Sn and TiB₂ phases in the composites without any other phase, such as TiAl₃ or AlB₂ phase and so on. In-situ TiB2 particles with nearly spherical form, are between 0.8μm and 1.2μm in size, and disperse mostly in the interface between α-Al and eutectic tin, which forms the microstructure of TiB2 particles covered with tin film. (2) Compared with matrix alloys, the composites have higher bearing capacity and wear-resistance, especially, exhibit better anti-friction under higher load, but the matrix alloys is excellent under lower load. (3) The friction coefficient and weight loss increased with the increasing of load. Mild abrasive wear dominated at lower load, a as well as mild adhesion wear and fatigue wear appeared under higher load. (4) With the...