Influence of Spark Plasma Sintering Preparation Reaction of Ni/SiCf System

Abstract:

As a new high-temperature material design with higher strength and lighter weight, researchers have paid attention to the SiCf reinforced nickel matrix composite. However, the severe interface reaction hinders the further development of this material. Since a long-time preparation could reduce the severe reaction, hence, in present work the Ni/SiCf composite system is prepared by spark plasma sintering which is characterized by shorter preparation time. SEM and EDS are used to analyze the interface morphology and element distribution. The results show that Ni reacts with SiCf and Ni3Si and carbon particles are formed. The reaction zone further reacts with Ni to generate Ni(Si,C) solid solution. There exist strong thermodynamic and kinetic conditions between Ni/SiCf system and Ni/Ni3Si system, which induce violent interface reaction. Raising sintering temperature and prolonging holding time could prompt Ni3Si and carbon particles to further dissolve. The dissolution process will shrink the reaction zone and expand the solid solution zone.

Key words:superalloy; composite; SiC fiber; interfacial reaction; spark plasma sintering