Abstract:

The traditional iron cylinder was characterized by poor matching with aluminium alloy cylinder block, and the long-term use might lead to oil and gas spilling. To solve these problems, a new type of cylinder liner made of aluminium gradient composites reinforced by complementary primary Si and Mg2Si particles was prepared by centrifugal casting and using the Al-19Si-5Mg-1Cu-1Ni-1Ti-1Mn alloy as raw material. Structurally, the composites were divided into two zones: a reinforced zone with high volume fraction of primary Si and Mg2Si particles and an unreinforced zone without or few particles. Through a preliminary test of some performance indicators of inner zone and outer zone under normal temperature, the reinforced zone is found to be characterized by the high hardness, high wear resistance and fine thermal stability. 

Key words: cylinder liner, centrifugal casting, primary Si, primary Mg2Si

摘要：

针对传统铁质气缸套与铝合金气缸体匹配性差，长期使用导致漏油、漏气等问题，提出了一种制备铝基梯度复合材料气缸套的新思路。依此思路，采用Al-19Si-5Mg-1Cu-1Ni-1Ti-1Mn合金为毛坯材料，通过离心铸造的方式成功制备了初晶Si与Mg2Si颗粒互补增强的铝基梯度复合材料。从心部到外壁，该梯度复合材料具有两层结构，内层含有高体积分数初晶Si与Mg2Si颗粒，形成增强层;外层没有初晶颗粒，为非增强层。对两层结构的部分常温性能指标进行初步测试，结果显示，增强层具有高硬度、高耐磨性和良好热稳定性的特点。

关键词: 气缸套, 离心铸造, 初晶Si;初晶Mg2Si