等离子加热反应合成TiB_2-B_4C-Fe_3(C,B)复合材料研究

TiB_2-B_4C-Fe_3(C,B) Composite Synthesized by Plasma Heating

以Ti、B4C和Fe粉为原料,采用等离子束加热反应合成TiB2-B4C-Fe3(C,B)复合材料,并研究复合材料的物相、组织结构和显微硬度。结果表明:反应生成物相主要有TiB2、B4C以及Fe3(C,B)。由于等离子束的快速加热、冷却以及散热具有方向性,板条状TiB2晶粒沿散热最快的方向生长,与白色的Fe3(C,B)相间分布,未反应的B4C被挤压在板条之间;等离子束电流影响单位时间内输入试样的热量,电流越大越有利于TiB2的长大,但降低复合材料硬度。

TiB2-B4C-Fe3（C, B） composites were prepared by plasma heating synthesis with Ti, B4C and Fe powders as raw materials. Effects of plasma current on phase composition, microstructure and hardness of the final composites were studied. The results show that the final composites are composed of TiB2, B4C and Fe3（C, B）. Because of fast heating and cooling during the plasma heating synthesis and directional heat releasing, plate-like TiB2 grains grow along the fastest heat releasing direction. TiB2 plates and white Fe3（C, B） are alternating distribution while the unreacted B4C grains are packed into gaps. Plasma current affects the heat which inputted into the sample in unit time. Hence, increasing current is conducive to the growth of TiB2, but decrease the hardness of the composites.