| Ternary boride hard cladding material is a new kind of cladding material with excellent comprehensive performance. It is widely used in aerospace, machinery,nuclear industry, automobile, metallurgy, mining and other fields. Due to the mismatch of the material properties on both sides of the interface, it has a great influence to the interface bonding strength, and the service life of the cladding material part. Based on the first principles method, this paper studies the interface properties of the ternary boride hard cladding material (α-Fe/Mo2FeB2) by using the simulation software Materials Studio to reveal the intrinsic microcosmic mechanism of the material properties. It has great significance to the optimization design of ternary metal boride cladding material part.Firstly,the interface property of the α-Fe(001)/Mo2FeB2(001) with the most stable station is studied. The surface models with different atomic layers are established. The models are tested and the optimal geometric surface model is determined. Based on the surface model, considering the influence of atomic stacking on the interface, the four different atomic stacking methods ofα-Fe(001)/Mo2FeB2 (001) interface model are established. The interface adhesion work, interface binding energy and fracture work of the four interface models are calculated respectively. The results show that the Fe+hollow interface is the most stable and the crack fracture is more likely to occur in the matrix phase or hard phase,while the Fe + B + top interface system is the most unstable. It is further studied that the electronic structure of the most stable Fe+hollow interface and the most unstable Fe+B+top interface. The results show that the interface strength of Fe+B+top is lower than that of Fe+hollow.Secondly, the interface property of the α-Fe(001)/Mo2FeB2(100) with the most unstable station is studied. The two different atomic stacking methods ofα-Fe(001)/Mo2FeB2(100) interface model are established. The interface adhesion work, interfacial bonding energy and fracture work of the two interface models are calculated respectively. It is shown that the Fe + hollow interface is more stable and the crack fracture is most likely to occur in the hard phase Mo2FeB2, while the Fe +top interface system is more unstable. The electronic structures of these two interfaces are further explored. The results show that the interface strength of Fe +Hollow is higher than that of Fe + top.Finally,based on the most unstable a-Fe (001)/Mo2FeB2 (100) interface model,an interface models with different dopant atoms X (X = C, Cr, Ni) are constructed.Each dopant atom difference on to the interface property is studied. The results show that, with one atom doping, only the Cr atom replaces B atom in the clad layer to improve the interface performance. The other dopant atoms can not improve but reduce the interface performance. However, when adding two Ni, it greatly improves the stability of the interface, and the Ni content increace will improve the stability of the interface. In the interface model with single atom X (X = C, Cr, Ni), the influences on the interface property of the doping atoms in the substrate and in the clad layer are carried out, respectinely. The results show that, the interface defect forming energy and adhesion work of the interface model with C atom in the clad layer are the smallest, indicating that the interface is most likely to form and the most unstable. The interface defect forming energy and adhesion work of the interface model with Cr atom in the clad layer are the largest, which shows that the interface is the most not easily formed and the most stable. |
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