Fabrication Research Of Ti/C Laminated Material Reactive Synthesis

In nature, some biominerals possess highly-ordered structures and exellentproperties after thousands of years’ evolution. Laminated material is a novel ofbiomimetic structure material, which simulate the framework of nature shell andnacreous layer. The special superposition of the laminated material makes it possible forresearchers to design and prepare new material with comprehensive performances. InUnited States, Britain and Germany, they have focused on the biomimetic laminatedcomposite materials, and trying to apply them in a wide range of areas such as aircrafts,cars and tanks. So, research on laminated materials has become an important directionin material science and engineering.In this paper, the laminated structure of TiC/Ti composite material with the sheetof Ti and C as raw materials was prepared by spark plasma sintering (SPS). The effectsof process parameters on the interface characteristics and mechanical properties ofinterfacial reaction were studied, and the mechanical properties of laminated materialwere characterized. Exploration of the laminated Ti film and TiC mixed powderpreparation and characterization were also studied. The results show that:In this study, we have successfully prepared the laminated structure of Ti/TiC/Claminated composite material, which has three-layer with alternating by spark plasmasintering. The reaction in Ti/C interface was diffusion-type. The elements Ti and C haveundergone certain diffusion in the interface junction. The tendency to spread wasgreater in the layer C to Ti than in the layer Ti to C. The reaction thickness increasedwith the temperature higher (1400℃~1510℃).1510℃was the highest sinteringtemperature in such sintering conditions. The reaction-diffusion between the atoms of Cand Ti were much easier with high pressure, but high pressure would extrude thereaction layer deformation. The more ambiguous between the interface layer of C andTi is, the better interfacial bonding with Ti/C thickness ratio increases.The main phase components of Ti/C laminated material interface reaction layerwere C and TiC. The layer thickness change from17.73μm (1400℃) to34.98μm(1510℃) with the sintering temperatureincreases. The Ti will partially melt when thesintering temperature is higher than1510℃and thus can not obtain Ti/C laminatedcomposite materials. The diffusion reaction layer increased with the increase ofsintering pressure, and the maximum reaction layer up to32.6μm of20MPa. There will have a partial fracture in the layer of C when the pressure is too high and thus laminatedmaterial can not be prepared. The thickness of reaction layer achieved33.58μmwith athickness ratio3.5:1when the layer thickness increases with the thickness ratio.The mechanical properties of Ti/C laminated material were characterized by testing,the optimum processes conditions were as follows: When the sintering temperaturereaches the maximum1510℃, the bending strength was1478.23MPa and the fracturepower of laminated material has the maximum215.09×103J/m2,which were calculatedand analyzed at the same time. The bending strength of laminated material is up to3939.19MPa when the pressure reached20MPa, and the fracture power reached thehighest value540.16×103J/m2.When the thickness ratio was3:1,the laminatedcomposite bending strength and fracture power reached the maximum3494.52MPa and614.89×103J/m2,respectively. The main crack propagation of Ti/C laminated materialwere crack deflection, crack parallel expansion and bifurcation of the crack tip passive,and these expansion paths were the main toughening mechanism.The powder of Ti and carbon mixed together to make the middle layer powder, andstacked with Ti film to prepare the Ti/TiC laminated materials, it were also explored byspark plasma sintering in the paper. The results show that: The diffusion reactionoccurred at the interface of laminated Ti film and TiC mixed powder. The highersintering temperature is, the more interfacial reaction layer was blurred and the morediffusion reaction happened. But this layered structure was not obvious. The laminatedmaterial samples were characterized by testing indicating that the layered structure wasquite obvious at the sintering temperature1400℃and the diffusion reaction at theinterface layer was more adequate. At this point, the hardness was nearly doubled.