基于金相组织调控的锡基巴氏合金B83性能改进

为提高滑动轴承巴氏合金层的性能，满足旋转机械高速、重载和高可靠性发展的需要，促进高端滑动轴承产品的研发，本文针对锡基巴氏合金B83进行了性能改进研究.根据B83的金相组织模型，分析金相特征与其力学、摩擦学性能之间的特殊联系，设计了在B83中加入微量的Ag(1%、3%)及石墨(1%)调整金相组织特征，进而改善其力学和摩擦学性能的技术路线，并以布氏硬度、抗压强度、摩擦系数及磨损量4个指标对B83改进前后的性能进行了对比.研究结果表明：添加微量的Ag和石墨均可以促进B83中硬质点的细化和均布，这对提高B83的力学和摩擦学性能有益，特别是添加1%Ag后B83的高温硬度获得了显著提高，而添加微量石墨使B83具有一定的自润滑性，干摩擦系数更加稳定.加入1%Ag后巴氏合金B83的使用性能得到明显提升，更适用于高速电主轴及微型燃气轮机轴承.

Property improvement of tin-based Babbitt B83 based on metallography control

In order to improve the properties of Babbitt layer, meet the requirements of rotating machinery, and further promote the development of high-end sliding bearing, the properties of tin-based Babbitt B83 were researched. According to the model of metallographic structure of B83, the special relations between metallographic features and mechanical and tribological properties were analyzed. The improvement method based on metallography control was designed by adding trace Ag (1%, 3%) and Graphite (1%) into molten B83, and four indexes (including Brinell hardness, compressive strength, friction coefficient and wear loss) were compared between B83 and improved B83. The research results indicate that adding trace Ag and Graphite into B83 both promoted refinement and uniform distribution of hard particles of B83, which is beneficial to the improvement of mechanical and tribological properties of B83, especially adding 1%Ag makes high temperature hardness improve remarkably, while adding trace graphite makes Babbitt have certain self-lubrication and friction coefficient more stable. Both mechanical and tribological properties of B83 adding 1%Ag were improved remarkably, which is more suitable for bearing of high-speed motorized spindle and micro gas turbine.