In-situ TiC Particles Reinforced Nano-composite Synthesized by Mechanical Alloying NiAl(Co)-TiC Powders
XIA Dong-sheng~1, LI Bo~2, GUO Jian-ting~3, LI Gu-song~3, YU Yan~1(1 Dalian Maritime University, Dalian 116026, China;2 The Northeast University, Shenyang 110006, China;3 Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
The in-situ dispersed TiC reinforced NiAl(Co) matrix nano-composites were obtained after four kinds of elemental powders, i. e. Ni_(50)-Al_(50-x)-Co_x+10%(volume fraction)TiC (x=5,10,20) and Ni_(50)-Al_(45)-Co_5+20%(volume fraction) TiC were mechanically alloyed in a high-energy ball mill. In the NiAl(Co) and TiC nano-compounds, the grain size of NiAl(Co) is only about 10nm and that of TiC is 35～50nm when ball-milling Ni_(50)-Al_(45)-Co_5-10% (volume fraction)TiC powders by the reaction mechanism of the explosive reaction. It was found that the initial time of the explosive reaction was delayed 20 minutes as the volume fraction of TiC was increased to 20%. NiAl(Co) and TiC nano-compounds were obtained using mechanically alloying Ni_(50)-Al_(40)-Co_(10)-10%(volume fraction)TiC powders. However, increasing with the content of Co, the mechanism of the forming process was changed from the explosive reaction (5% Co, atom fraction) to the inter-diffusion reaction (10%Co, atom fraction). The γ-Ni(Al, Co, Ti, C) super saturation solid solution were formed during ball-milling Ni_(50)-Al_(30)-Co_(20)+10% (volume fraction)TiC with inter-diffusion reaction mechanism.