注射成形钨合金弹芯材料的性能与组织特征

研究开发低成本钨合金的近净成形技术是钨合金的一个重要发展方向。针对直径较大(Φ20～25mm)的钨棒弹芯和钨环散弹弹芯材料的注射成形,对粘结剂进行一系列的改进。采用一种粘度适中、流动性好、流变稳定性好的油+少量蜡组成的新型半固态塑料体系粘结剂,和多组元低分子混合溶剂快速脱除注射坯中60％以上的粘结剂,再采用热脱脂脱除其余的粘结剂,然后烧结,制备了性能很高的钨环和钨棒弹芯材料。研究了弹芯材料的性能和组织特征。结果表明,由弹芯加工成的冲击试样断口和拉伸试样断口形貌呈显著的钨晶粒穿晶解理断裂。采用注射成形工艺可以得到具有较高综合力学性能的钨合金弹芯。对于大截面的钨棒弹芯,弹芯材料的拉伸性能、延伸率和冲击性能分别达到σ_b=965MPa,δ=23％,A_k=54.4J/cm~2。

Properties and microstructural characteristics of powder injection molded tungsten alloy penetrators

To research and develop powder injection molding technology is a key point for tungsten heavy alloy processing. To aim directly at powder injection molding of penetrators with large diameter or very thin discs, by improving binder composi- tions, a kind of new half - solid binder system with adaptable viscosity, good moldability and stable rheology is used, and solvent debinding technology is used to remove more than 60% binder by soaking in a kind of multicomponent low - molecular solvent, then through thermal debinding and sintering, high - property tungsten discs and tungsten penetrators are prepared. The properties and microstructural characteristics are studied. The tungsten penetrators are processed to tensile bars and impact bars, then the tensile properties and impact toughness of theirs are measured, and their fracture morphologies are observed using SEM. The results show that the main fractures occur through tungsten grains. High - property tungsten pen- etrators can be prepared by powder injection moulding process, the properties of the prepared large - sized samples are:σ_b= 965MPa, δ=23%, A_k=54.4J/cm~2.