Abstract
Nanocomposites are wear resistant materials used in cutting toAbstract Nanocomposites are wear resistant materials used in cutting tool applications. The materials are composed of ultrafine powder hard phase grains surrounded by a tough binder phase carbon nanotubes (Mo2C)1-x(TiC)x (2≤x≤4)//1Wt% SWCNTs. Composite bicarbide Mo2C-TiC was rapidly synthesised and simultaneously consolidated by Field activated sintering technique (spark plasma sintering) at which the extensive volume expansion occurred as a function of the volumic fraction from 20 to 40 vol.% of TiC powders and 1 Wt.% of SWCNTs as reinforcement of the CMNC’s. The sintered powder mixture was examined by XRD patterns, the morphology of the obtained phase was observed by SEM and the phase compositions in different regions were analyzed by EDX. The composites were processed using Field Activated Sintering Technique, spark plasma sintering (SPS) at temperatures in the range of 1700-1800℃ with addicting of SWCNTs. The effects of SWCNTs addition on phases morphology, microstructure hardness and fracture toughness of the nanocomposite were investigated. The best product contained 1.0 Wt.% SWCNTs from (Mo2</subC) 1-x</sub(TiC)x</sub, x= 0.2 which was sintered at 1700 ℃, 70 MPa for 10 min, M0.8T0.2/ 1 Wt% SWCNTs exhibit a better density, highest hardness and a good ductility. Relative densification was achieved 99.5 % from the theoretical and a good mechanical properties like hardness and fracture toughness (KIC =5.6 Mpa m1/2) are enhanced. The results were confirmed using Raman spectroscopy.ol applications. The materials are composed of ultrafine powder hard phase grains surrounded by a tough binder phase carbon nanotubes (Mo2C)1_x–(TiC)x (2≤x≤4)//1Wt% SWCNTs. Composite bicarbide Mo2C-TiC was rapidly synthesised and simultaneously consolidated by Field activated sintering technique (spark plasma sintering) at which the extensive volume expansion occurred as a function of the volumic fraction from 20 to 40 vol.% of TiC powders and 1 Wt% of SWCNTs as reinforcement of the NCMC's. The sintered powder mixture was examined by XRD patterns, the morphology of the obtained phase was observed by SEM and the phase compositions in different regions were analyzed by EDX. The composites were processed using Field Activated Sintering Technique, spark plasma sintering (SPS) at temperatures in the range of 1700-1800℃ with addicting of SWCNTs. The effects of SWCNTs addition on phases morphology, microstructure hardness and fracture toughness of the nanocomposite were investigated. The best product contained 1.0 Wt% SWCNTs from (Mo2C)1_x–(TiC)x, x= 0.2 which was sintered at 1700 ℃ , 70 MPa for 10 min, M0.8T0.2/ 1 Wt% SWCNTs exhibit a better density, highest hardness and a good ductility. Relative densification was achieved 99.5 % from the theoretical and a good mechanical properties like hardness and fracture toughness (KIC=5.6 Mpa m1/2) are enhanced. The results were confirmed using Raman spectroscopy.
Highlights
Nanomaterials have been the subject of extensive research in recent years due to their extraordinary properties over their conventional counterparts
XRD analysis of the samples indicates that the only phases formed in the sample without SWCNTs are titanium carbide TiC, with a cubic crystal structure and Mo2C with orthorhombic crystal structure
XRD spectrum of the (NCMC’s), which indicates that the reaction between the TiC powders and SWCNTs did happen during the sintering process
Summary
Nanomaterials (defined as being in the size range 1-100 nm in at least one dimension) have been the subject of extensive research in recent years due to their extraordinary properties over their conventional counterparts. The present paper highlights some key issues related to powder synthesis and sintering of composite Mo2C-TiC -based nanostructured materials using mechanical alloying. It should be noted that the names ECAS [2], and field activated sintering technique (FAST) [3] were introduced to designate the consolidation methods based on the application of a electric field/current regardless their waveforms, while pulse electric current sintering (PECS) was used by some authors as a generalization of RS methods which involve the application of a pulsed electric current [4] It should be pointed out once more that the applied characteristics and/or the apparatus adopted were in some cases not specified. In the spark plasma sintering process, temperature profile and punish displacement or shrinkage the displacement velocity is not presented here (Figure.1b)
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