注射成形钨合金的显微结构对其力学性能的影响

来源期刊：中南大学学报(自然科学版)2004年第5期

论文作者：范景莲 黄伯云

文章页码：714 - 719

关键词：注射成形;钨合金;显微组织;性能

Key words：injection molding; tungsten alloy; microstructure; properties

摘    要：采用一种新型半固态塑料体系粘结剂和多组元低分子混合溶剂进行快速溶剂脱脂、热脱脂、烧结,制备了性能较高的拉伸试样、冲击韧性试样和钨棒弹芯材料。测试了拉伸试样、冲击韧性试样及弹芯材料的显微组织与性能,研究了显微组织结构特征对其力学性能的影响。研究结果表明,注射成形弹芯材料的力学性能都优于传统方法制备的弹芯材料的力学性能,其拉伸断口和冲击断口均呈现大量的钨晶粒穿晶解理断裂;与标准拉伸样和冲击样相比,弹芯厚度较大的试样,完全脱除粘结剂很困难,试样中仍存在少量残留杂质,这些杂质大部分存在于晶界,使其冲击断口和拉伸断口上呈现较多的钨晶粒沿晶断裂,导致弹芯材料合金性能降低;烧结温度对断口形貌和力学性能也有较大影响。

Abstract: By a new half-solid plastic polymer binder and a multi-low molecule mixed solvent with rapidly solvent debinding and subsequent thermal debinding and sintering, three kinds of samples with good properties, the standard tensile bars, the rectangle bars for testing impact toughness and the tungsten alloy penetrator bars were prepared. The microstructure and properties of the samples were tested. The results show that the mechanical properties of the tensile bars, the rectangle bars and the penetrator bars prepared by using injection molding have better properties than those of by traditional P/M method. The tensile and impact fracture characteristic contains mainly fracture cracks cutting through spherical tungsten grains. However , for the thicker cross-sections penertrator , the plastic polymer is very difficult to remove completely , after debinding and sintering , a small amount of inclusion still exist on the boundaries. In comparison with the standard tensile bars and rectangle bars,the tensile and impact fracture surfaces of the penetrator bars have more fracture cracks along tungsten-tung-sten grains and tungsten-binder grain boundaries,which lead to the decrease of tensile properties and impact toughness. Sintering temperature has also great influences on fracture characteristic and properties.