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

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.