1. 基于黄培云粉末压制理论，导出了环形粉末预制坯相对密度沿高度分布计算公式，以及环形粉末预制坯上下端面密度的比值。
Furthermore the calculation formula of density distribution for ring preform is derived based on the Huang's pressing theory, the ratio of up end density to low end density is calculated, which is useful for technology design of pressing ring preform.