Effect of boron addition on mechanical properties of Fe-Ni-Mo-B-C sintered alloys

Egashira, Shigeki; Sekiya, Takashi; Ueno, Tomoyuki; Fujii, Masahiro

doi:10.1299/mej.19-00297

Cited by 6 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There have been some reports regarding to the effect of Cu, Ni or Mn on the microstructure and properties of the Fe-B-C alloys [16][17][18][19]. However, their examined compositions have been limited up to 3 wt.…”

Section: Introductionmentioning

confidence: 99%

Solubility of Cu, Ni, Mn in Boron-Rich Fe-B-C Alloys

Sukhova

2021

Phys. Chem. Solid St.

View full text Add to dashboard Cite

In the present study, the microstructure development and mechanical properties of the cast boron-rich Fe–B–C alloys cooled at 10 and 103 K/s were investigated as functions of alloying elements additions. These alloys were prepared in the following compositional ranges: B (10–14 wt.%), C (0.1–1.2 wt.%), M (5 wt.%), where M – Cu, Ni or Mn, balance Fe. Structural properties were characterized by quantitative metallography, X-Ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. Mechanical properties of the structural constituents, such as microhardness and fracture toughness, were measured by a Vickers indenter. Copper becomes negligibly incorporated into the phases Fe(B,C) and Fe2(B,C) of the Fe–B–C alloys, but solubility limit forces the remaining solute into the residual liquid. As a result, the globular Cu inclusions are seen in the structure. As compared with copper, nickel has higher solubility in the constituent phases, with preferential solubility observed in the Fe2(B,C) crystals, where Ni occupies Fe positions. Having limited solubility, nickel also forms secondary Ni4B3 phase at the Fe2(B,C) boundaries. Manganese was found to dissolve completely in the Fe–B–C alloys forming substitutional solid solutions preferentially with Fe(B,C) dendrites. By entering into the iron borides structure, Mn and Ni improve their ductility but lower microhardness. The peculiarities in the structure formation and properties of the doped boron-rich Fe–B–C alloys were explained with electronic structure of the alloying elements considered.

show abstract

Section: Introductionmentioning

confidence: 99%

Solubility of Cu, Ni, Mn in Boron-Rich Fe-B-C Alloys

Sukhova

2021

Phys. Chem. Solid St.

View full text Add to dashboard Cite

show abstract

“…The authors have developed a liquid phase sintering method achieving high density without secondary processing, for the purpose of achieving both high strength and low cost (Egashira et al, 2019;Egashira et al, 2020). In our previous study, the effect of the addition of boron on the rolling contact fatigue strength of the Fe-Ni-Mo-B-C sintered and carburized materials has been evaluated.…”

Section: Introductionmentioning

confidence: 99%

Effect of boron addition on the gear fatigue strength of Fe-Ni-Mo-B-C sintered alloys

Egashira

Ishimine

Ueno

et al. 2022

Mechanical Engineering Journal

Self Cite

View full text Add to dashboard Cite

Iron-based sintered alloy materials have a problem with fatigue strength because the number of pores contained in the material is 10% by volume. Therefore, sintered materials are not applicable to gears used under high speed and high load, such as transmission gears for automobiles. The authors have developed a high fatigue strength sintered gear using the liquid-phase sintering method. In this study, Fe-Ni-Mo-B-C sintered and carburized gears with different boron contents were fatigue-tested using a gear testing machine. The sintering densities of each test gear were controlled to be the same in order to evaluate only the effect of boron addition on fatigue strength. The gear fatigue limit (p max ) lim of a boron-free gear (the 0.0BG), 0.1 mass% boron added gear (the 0.1BG) and 0.4 mass% boron added gear (the 0.4BG) were 1750 MPa, 2150 MPa and 2000 MPa, respectively. The addition of boron was effective in improving gear fatigue strength. A comparatively large difference was confirmed in the pore shape between the boron-free material (the 0.0BG) and the boron-added material (the 0.1BG, the 0.4BG). That is, while the pores of the 0.0BG were irregularly shaped, those of the 0.1BG and the 0.4BG were spherical. Since these spherical pores suppressed the generation and propagation of cracks during the fatigue test, the fatigue strength could be improved by the addition of boron. In addition, the 0.4BG had a brittle Fe 23 B 6 network microstructure that was not seen in the 0.1BG. The reason why the fatigue strength of the 0.4BG was lower than that of the 0.1BG was considered to be due to the formation of network-like Fe 23 B 6 in the 0.4BG.

show abstract

“…[31,32] Likewise, the addition of the appropriate alloying elements was beneficial to the densification of boron-containing alloys; however, the improvement of elongation property was very limited because a large amount of liquid phase produced the continuous network of eutectic hard phases [M 23 B 6 , M 3 (C, B), and M 2 B] at the grain boundaries. [33,34] Recently, the mechanical properties of liquid phase sintered alloys have been studied based on the microstructural modification, which prevented the continuous network of eutectic phases and increased the grain continuity. [35][36][37] Several studies suggested that the microstructure of boron-containing alloys can be modified by composition [9,12] and heat treatment.…”

Section: Introductionmentioning

confidence: 99%

Microstructure Modification of Liquid Phase Sintered Fe–Ni–B–C Alloys for Improved Mechanical Properties

You

Kim

Lee

et al. 2021

Metall Mater Trans A

View full text Add to dashboard Cite

Powder metallurgy (P/M) has been widely used in automobile, home appliances, and electronic devices, but its uses are very limited due to the low relative density of 85 to 95 pct. The Fe-Ni-B-C alloy system can mitigate the aforementioned issues by the liquid phase sintering, which results in a nearly full densification. However, the boron-containing alloys produced the brittle eutectic phases [Fe 3 (C, B) and Fe 2 B] along the grain boundaries, which are detrimental to the mechanical properties. The main objective of this study is to improve the ductility of boron-containing alloys through the microstructure modification. For this, the volume fraction of solidified phase was optimized by controlling the composition, and the coarsening of solidified a-Fe particles into the pearlite matrix was induced by a post annealing, which reduces the continuous network of eutectic phases and increased the grain continuity. In addition, the effect of microstructure modification on the mechanical properties of Fe-B-C and Fe-Ni-B-C alloys was comparatively investigated. As a result of microstructure modification, the postannealed Fe-1Ni-0.4B-0.8C alloy exhibited a high elongation to failure of 5.2 pct.

show abstract

Effect of boron addition on mechanical properties of Fe-Ni-Mo-B-C sintered alloys

Cited by 6 publications

References 12 publications

Solubility of Cu, Ni, Mn in Boron-Rich Fe-B-C Alloys

Solubility of Cu, Ni, Mn in Boron-Rich Fe-B-C Alloys

Effect of boron addition on the gear fatigue strength of Fe-Ni-Mo-B-C sintered alloys

Microstructure Modification of Liquid Phase Sintered Fe–Ni–B–C Alloys for Improved Mechanical Properties

Contact Info

Product

Resources

About