(中南大学 粉末冶金国家重点实验室,长沙 410083)
摘 要: 以硬质合金材质体系为对象,针对目前主要的一类挤压成形设备—真空螺杆挤压机,开发出了一种增塑粉末挤压成形新技术。从理论上系统分析了成形过程的物理本质及粘结剂非等温热脱脂机理与动力学,并推导出了一系列流变学材料函数。理论分析与实验相结合,开发出了一种多组元新粘结剂设计与制备技术,优化了挤压工艺参数,制备出了直径20mm的硬质合金挤压棒。
关键字: 增塑粉末挤压成形新技术;粘结剂;热脱脂;流变学;硬质合金
powder extrusion molding
(State Key Laboratory for Powder Metallurgy,
Central South University,Changsha 410083,China)
Abstract:For vacuum worm type extrusion press,the physics essence of plasticizing powder extrusion molding (PEM) process based on a novel binder system,and u sing cemented carbide powder as a test material,has been analyzed.The material functions have been deduced by rheological method. The non-isothermal debinding mechanism and dynamics of binder and extrusion molding bodies was studied by thermogravimetric analysis method. Combined with theoretical analyses and experimental results,a novel multi-component binder has been developed successfully,and the PEM processes parameters and condition were optimized. The cemented carbides PEM rods,with diameters up to 20mm are manufactured.
Key words: novel technology for PEM;binder;rheology; thermal debinding;cemented carbides