In this paper , the vsi is produced by powder metallurgy . various alloy elements added , porosity and microstructure of materials is considered to affact the vsi ' s property ; matching between the working and none - working layer of vsi is discussed ; and the cost reduction of two - layer vsi is analysed as well 研究了各種合金元素的添加、孔隙率和顯微組織對(duì)閥座圈工作性能的影響;討論了雙層閥座圈工作層與非工作層之間的匹配;分析了雙層閥座圈在成本上的優(yōu)勢(shì)。