The Influence of the Third Element on Nano-Mechanical Properties of Iron Borides FeB and Fe2B Formed in Fe-B-X (X = C, Cr, Mn, V, W, Mn + V) Alloys

Abstract

In this study, the influence of alloying elements on the mechanical properties of iron borides FeB and Fe2B formed in Fe-B-X (X = C, Cr, Mn, V, W, Mn + V) alloys were evaluated using instrumented indentation measurement. The microstructural characterization of the alloys was performed by means of X-ray diffraction and scanning electron microscope equipped with an energy dispersive X-ray analyzer. The fraction of the phases present in the alloys was determined either by the lever rule or by image analysis. The hardest and stiffest FeB formed in Fe-B-X (X = C, Cr, Mn) alloys was observed in the Fe-B-Cr alloys, where indentation hardness of HIT = 26.9 ± 1.4 GPa and indentation modulus of EIT = 486 ± 22 GPa were determined. The highest hardness of Fe2B was determined in the presence of tungsten as an alloying element, HIT = 20.8 ± 0.9 GPa. The lowest indentation hardness is measured in manganese alloyed FeB and Fe2B. In both FeB and Fe2B, an indentation size effect was observed, showing a decrease of hardness with increasing indentation depth.

Prediction of phase composition and mechanical properties Fe–Cr–C–B–Ti–Cu hardfacing alloys: Modeling and experimental Validations

“…The latter is explained by inherent brittleness of Fe 2 B due to the week B–B bond along [002] direction [ 77 , 78 ], which leads to a great susceptibility of boron alloys to cracking. Kirkovska et al [ 79 ] showed that among the alloying elements C, Cr, Mn, V, W, Mn + V, the greatest increase in the indentation modulus of both monoboride FeВ and hemioboride Fe 2 B, was observed in alloying with chromium. Whereas the lowest modulus in the case of FeB formed in Fe–B–X (X = C, Cr, Mn) was measured in the presence of C as an alloying element, while for Fe 2 B, in Mn alloyed Fe 2 B.…”

“…At that, Fe 2 B with a tetragonal lattice is less brittle. Further improvement of the mechanical properties of hemioboride due to additional alloying of the boride [ 67 , 79 ] elements (Ti, V, Cr, Co, Ni, and Cu) showed that it can enhance the ductility of the Fe 2 B, but cannot change the intrinsic brittle nature of the Fe 2 B [ 67 ]. Copper increases the plastic properties of hemioboride most of all the range of alloying elements M = Ti, V, Cr, Mn, Co, Ni and Cu (Fe 0.875 M 0.125 ) 2 B, at the same time, the value of G/B (0.5883) is close to the critical value of the ductile/brittleness transition (0.571) [ 67 ].…”

Crystallization of Fe-W-B Amorphous Powder Prepared by Gas Atomization

“…Metallic glasses have unique combinations of mechanical properties, corrosion resistance and magnetic property due to their non-crystalline structure. In recent years, more and more studies have focused on metallic glass, such as amorphous nanocrystalline powder, amorphous strips and so on [12][13][14][15][16]. A kind of amorphous Fe-W-B nano-powder was obtained via a chemical method [17]; nevertheless, the low yield makes it difficult to realize mass production.…”