一、前言 人们最早是通过粉末冷压制再高温烧结而制成粉末制品的,后来又发展了一种同时完成成型和烧结二个工序的热压成型工艺。这二种成型工艺均是轴向机械压制,由于距外加应力点越远,外应力的损耗就越大,而“净应力”就越小(“净应力”系指使粉末位移、变形、克服粉末内摩擦使压坯密度提 First, the foreword The earliest people through the powder cold pressed and then sintered at high temperature made of powder products, and later developed a molding and sintering at the same time to complete the two processes of hot forming process. Both of these molding processes are axial mechanical compression. As the distance from the applied stress point increases, the loss of external stress increases and the “net stress” decreases (“net stress” means displacement, deformation of the powder, Internal friction to make compact density mention