【摘要】 研究了坯料尺寸对等径角挤压材料等效应变及单位挤压力的影响.采用有限元法分析了不同尺寸坯料在不同摩擦条件下等径角挤压后的等效应变大小、分布与单位挤压力.结果表明,在坯料尺寸相同的情况下,随着摩擦系数的增大,坯料横截面上的等效应变略有增加,单位挤压力明显增加.在摩擦系数相同的情况下,不同尺寸坯料横截面上的等效应分布和大小基本一致,单位挤压力随坯料尺寸的增加而下降.这表明只要采用合理的润滑和模具结构,利用等径角挤压工艺可以制备出满足工业化应用要求的大块体超细晶材料.更多还原

【Abstract】 The effect of billet size on the effective strain and unit extrusion pressure was investigated during equal channel angular pressing.Magnitude,distribution of the effective strain and unit extrusion pressure after equal channel angular pressing in different size billets were analyzed by finite element method under different friction conditions.The results show that the effective strain along cross-section of billet increases slightly,and the unit extrusion pressure increases obviously with the increase of friction coefficient.Under the condition of the same friction coefficient,magnitude and distribution of the effective strain along cross-section of billet are identical in substance,and the unit extrusion pressure decreases with the increase of the billet size.It shows that the big bulk ultra-fine grained materials for industrial application can be produced by equal channel angular pressing process as long as reasonable lubrication and die geometry are adopted.更多还原