【摘要】 粉末锻压工艺是粉末成形新技术之一。本文对相当于20和40号铜的铁与石墨的混合粉末,在低于其相变点的不同温度、不同压力下的锻压成形机理进行了试验研究。扫描及透射电镜图象表明,铜的混合粉末不经单独的烧结工序,在低于其相变点的温度下进行高压温锻,强烈的塑性变形使混合粉末成为有晶界的金属整体。温锻后的相对密度达98％,明显地高于经一般性烧结后的金属粉末制品,有利于提高制品的硬度、强度等机械性能及尺寸精度、表面光洁度。更多还原

【Abstract】 Mixed carbon steel powder particles (0.2% and 0.45%C) were forged under va- rious pressures below 700℃. Significant plastic flow of powder particles occurs in warm forging and leats to nearly theoretical density.SEM and TEMmicrographs show that crystallization of powder particles occurs during plastic flow and fresh grain boundaries have been formed after warm forging. Products warmly forged may have better physical and mechanical properties and dimensional aecuraey compared with sin- tered powder products and hot forging products of sintered powder preforms。There- fore, warm forging of powders is a promising new technology。更多还原