纳米碳化钽对SPS烧结钨显微结构的影响

Effect of Nano-TaC on Microstructure of Sintered Tungsten by SPS

摘要:

通过放电等离子体烧结 (SPS) 方法在1700 ℃下制备纳米碳化钽 (TaC) 弥散强化钨块，研究钨粉原始粉末粒度大小和添加碳化钽的量对烧结钨块微观组织的影响。结果表明：不同粒度钨粉 (30 nm、200 nm和3 μm) 制备的钨块，烧结后的粒径随原始粉末粒度的增大而增大，3 μm钨粉烧结后的晶粒平均直径为22.19 μm；同一种粒度钨粉 (如200 nm)中分别添加质量分数为0%，1%，2%和4%的碳化钽，烧结后钨晶粒的平均直径随碳化钽添加量的增加而减小，加入量为4%时晶粒平均直径为5.91 μm。通过SEM分析可以看出，碳化钽在烧结钨中是以球形状态存在的。从断口可以看出，纯钨烧结体为穿晶断裂，加入碳化钽的钨烧结体为晶间断裂

Abstract:

Dispersion strengthened tungsten with nano-tantalum carbide (TaC) was prepared by Spark Plasma Sintering (SPS) process at 1700 ℃ for 1 min. The results show that the grain size of tungsten will be larger if the particle size of tungsten powder is larger. When the particle size of tungsten powder is 3 μm, the grain size of tungsten is 22.19 μm. And then, with the increase of TaC content, the grain size of tungsten will be finer. When the particle size of tungsten powder is 200 nm and the content of TaC is 4%, the grain size of sintered tungsten is about 5.91 μm. It also can be seen that TaC is spherical, it exists at grain boundaries of the sintered tungsten. Some transgranular fracture can be seen in fracture surface of pure tungsten by SPS, but it is mainly intergranular fracture in fracture surface of dispersion strengthened tungsten with nano-tantalum carbide