Theoretical Study of The Alloying Elements on the Properties of Tib₂ Ceramic Reinforced Fe Matrix Composite

In recent decades, ceramic particles reinforced iron matrix composites (CPRIMCs) are regarded as the main achievements in wear resistant materials area [1-3]. Among many iron matrix composites, Tib₂ ceramic reinforced Fe matrix composite (Tib₂/ Fe) behaves large elastic modulus, high mechanical strength, and advanced hardness and wear resistance [4,5]. Additionally, the high electrical conductivity of Tib₂ ceramic [6] enables machining of Tib₂/Fe composite easily using electrical discharge machining. Agarwal and Dahotre [7] discussed the reinforcing mechanism of Tib₂/Fe composite, the epitaxial growth of iron on Tib₂ particles is revealed, and the orientation relationship was found as Tib₂ (0001)/Fe (111). However, much less information is available for the effects of alloying elements on the properties of Tib₂/Fe interface.

We use the method proposed in [8] to investigate the atomic structures, chemical bonding, stability and fracture mechanism of Tib₂/Fe composite. It is found that B-terminated interface with HCP site behaves the most stable nature and belongs to non-diffusive configuration. Based this configuration, the segregation behavior of alloying additives X (X=Si, Al, Cr, Mn, Ni, Mo) on the interface of Tib₂ ceramic reinforced iron matrix composite as well as the effects of these additives on the interfacial adhesion, electronic and magnetic properties were studied. The results indicated that Cr, Mn and Mo may segregate at the Tib₂ (0001)/Fe (111) interface because of their low heat of segregation barrier (Figure 1).

Moreover, compared with the work of adhesion of different alloying doping interfaces, the introduction of Cr, Mn improves the adhesive strength of Tib₂(0001)/Fe (111) interface through strong covalent interactions between Cr/Mn and B atoms. The best strengthening effect on Tib₂ (0001)/Fe (111) interface can be attributed to Mn because of the highest interfacial work of adhesion and critical stress of Mn-doped interface; we also found the interfacial work adhesion energy is high than fracture energy of Tib₂ and Fe slabs, indicating the mechanical strength of the interface is more remarkable than both Tib₂ and Fe bulks, and the mechanical failure will initiate at the Fe interior.

From the soft carbons/graphite to carbon nanostructures, such as graphene/CNTs/graphdiyne and nanocomposites with CNTs/graphene, the capacities have been boosted obviously and thus the performance of anode has been enhanced. Nano carbons can be also used in cathode as efficient conductive additives. It is foreseeable that Nano carbons will make a major role in the coming new-generation LIBs.

This work was supported by the Natural Science Foundation of Shaanxi Province of China (2018JM5002), the Key Research and Development Program of Shaanxi Province of China (2019GY- 182), the Postdoctoral Science Foundation funded Project of China (No. 2018M631152, 2018T111051), the Postdoctoral Science Foundation funded Project of Shaanxi Province of China, the Fundamental Research Funds for the Central Universities of China (xzy012019001), the Guangxi Innovation Driven Development Project (GUIKEAA18242001).

No conflict of interest.

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