[en] Highlights: ► Nine tri-phase regions exist in the Co–Si–Zn system at 723 K. ► Eight tri-phase regions exist in the Co–Si–Zn ternary system at 873 K. ► The CoSi phase can coexist with all compounds in Co–Zn binary system except β₁ phase. ► The solubility of Si in Co–Zn binary compounds is limited. ► Zn solubilities in CoSi and Co₂Si are higher than that in CoSi₂. - Abstract: The 723 and 873 K isothermal sections of the Co–Si–Zn system have been determined using equilibrated alloys with the aid of a diffusion couple approach. The specimens were investigated by means of scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, electron probe microanalysis and X-ray diffraction. There are nine three-phase regions exist in the isothermal section at 723 K and eight three-phase regions at 873 K. The CoSi phase can coexist with all compounds in Co–Zn binary system except β₁ phase. The solubility of Si in Co–Zn binary compounds is limited. The maximum solubility of Zn in CoSi₂, CoSi and Co₂Si is 2.0, 6.2, and 5.4 at.%, respectively.

[en] Highlights: •The 600°C and 450°C isothermal sections of the Zn-Fe-B system are determined. •The solubility of Zn in Fe₂B and FeB at 600°C is 1.8 at.% and 2.5 at.%, respectively. •The solubility of Zn in Fe₂B and FeB at 450°C is 1.7 at.% and 2.1 at.%, respectively. •All Fe-Zn compounds can be in equilibrium with Fe₂B at 450°C. •Both FeB and Fe₂B are in equilibrium with the liquid phase at 600°C. -- Abstract: The isothermal sections of Zn–Fe–B ternary system at 600 °C and 450 °C have been determined experimentally using scanning electron microscopy, electron probe microanalysis and X-ray diffraction. Five three-phase regions exist in the isothermal section at 600 °C, seven three-phase regions exist at 450 °C. The experimental results indicate that B is almost insoluble in Fe–Zn compounds and α-Fe. The solubility of Zn in Fe₂B and FeB at 600 °C is 1.8 at.% and 2.5 at.%, respectively, and that at 450 °C is 1.7 at.% and 2.1 at.%, respectively. All Fe–Zn compounds can be in equilibrium with Fe₂B, the equilibrium between FeB and ζ prohibits the coexistence of Fe₂B and liquid at 450 °C. Both FeB and Fe₂B are in equilibrium with the liquid phase at 600 °C

[en] The 800 C isothermal section of the Co-Cr-Mo-Si quaternary system with the Co content fixed at 70 at.% and different contents of Cr, Mo and Si was determined by means of X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Twelve different phase regions could be identified; one of them being a wide (Co) + Co₃Mo₂Si phase field, but only one four-phase region consisting of (Co) + Co₃Mo + Co₇Mo₆ + Co₃Mo₂Si was experimentally confirmed. The measured solubility of Si in the Co₃Mo phase is rather limited but could reach up to 15.1 at.% in Co₇Mo₆. The solubility of Cr in Co₃Mo and Co₇Mo₆ was measured to be as high as 13.4 and 23.3 at.%, respectively, and the maximum solubility of Cr in (Co), αCo₂Si and Co₃Mo₂Si could reach 26.9, 5.6 and 12.5 at.%, respectively.

[en] The 700 C isothermal section of the Fe-Cr-Si ternary phase diagram has been determined experimentally by means of scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and X-ray powder diffraction. Ten three-phase regions exist in the 700 C isothermal section. The binary σ phase contains 0-17.6 at.% Si and 31.4-59.2 at.% Cr; the Fe₅Si₃ phase is stable at 700 C because of the dissolution of Cr. At this temperature, Fe and Cr cannot be entirely substituted by each other to form the FeSi or CrSi phases: the maximum possible Cr content in FeSi₂, Fe₅Si₃ and D0₃ is 3.9, 20.7 and 15.2 at.%, respectively, and the maximum soluble Fe in CrSi₂, Cr₅Si₃ and Cr₃Si is 2.5, 20.4 and 16.8 at.%, respectively.

[en] The corrosion behaviors of Fe–3.5B alloys to molten zinc at 450, 520, and 600 °C were investigated by x-ray diffraction, scanning electron microscopy, electron probe micro-analysis, and micro-hardness testing. The corrosion depth of the tungsten-free alloy to molten zinc was 6–3 times thicker than that of W-containing alloy, but the thickness of transition zone for W-containing alloy was 5–30 times thicker than the tungsten-free alloy at different temperatures, respectively. The complete skeleton of reticular borides, high hardness, and thick transition zone of the corrosion layer conduced to the excellent spallation resistance of the borides modified by W addition. Furthermore, the phase transition and corrosion damage of the (Fe,W)₃B and FeWB in molten zinc were also researched. (paper)

[en] Highlights: • Further studied the phase relationship of Co-rich corner at 250 °C. • Newly investigated the 650 and 450 °C isothermal sections of Co-Sn-Zn system. • A set of self-consistent thermodynamic parameters for Co-Sn-Zn system was obtained. Phase equilibria in the Co–Sn–Zn ternary system have been systematically investigated by combining experimental measurements with thermodynamic modelling. The phase relations in the Co–Sn–Zn system at 650, 450 and 250 °C were investigated using scanning electron microscopy coupled with energy–dispersive X–ray spectroscopy and X–ray diffraction. Based on the present experimental results and a comprehensive evaluation of the data reported in the literature, a thermodynamic description of the Co-Sn-Zn system was developed using the CALPHAD technique. A set of self–consistent thermodynamic parameters for the Co–Sn–Zn ternary system was obtained with a reasonable agreement between the experimental and calculated results.

[en] The 620 C isothermal section of the Al-Zn-Fe-V quaternary system with the Al content fixed at 55 wt.% and the Al-rich corner of the Al-Fe-Zn ternary system at 620 C have been determined by means of scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and X-ray diffractometry. Two four-phase regions are identified in the isothermal section of the Al-Zn-Fe-V quaternary system. Two three-phase regions are found in the Al-rich corner of the Al-Fe-Zn ternary system. No new ternary and quaternary phases have been found in the present work.

[en] The 450 deg. C isothermal section of the Zn-Al-Fe-Si quaternary system with Zn being fixed at 93 at.% has been studied experimentally by means of optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. Three Al-Fe-Si ternary phases, τ₁, τ₂₃ and τ, have been found in this section and the Zn solubility in those three phases are 6.9, 8.3 and 5.9 at.%, respectively. FeSi was found to be in equilibrium with FeSi₂, Si, η-Zn, τ₁, ζ and τ. The Al solubility in the FeSi phase is 11.2 at.%, and that in the FeSi₂ phase is rather limited. The Zn-Al-Fe ternary phase T(Fe₈Al₆Zn₈₆) was found to be in equilibrium with η-Zn, Fe₂Al₅ and τ₁ phase. Experimental findings indicated the possibility of three-phase equilibrium between FeSi, FeSi₂ and Si. The obtained isothermal section of Zn-Fe-Al-Si quaternary is compatible with the Zn-Al-Fe, Zn-Al-Si and Zn-Fe-Si ternary systems. Because of the lack of the precise Al-Fe-Si system phase relations at 450 deg. C, the checking of the consistency with this system needs more works

[en] The phase diagram of the Ni-Cr-Al-Y system can provide theoretical guidance for the composition design of NiCrAlY alloy coated on the surface of Ni-based superalloy, and as Ni-Cr-Y is a sub-ternary system of Ni-Al-Cr-Y, its phase relationship is the basis in establishing the thermodynamic database of Ni-Al-Cr-Y system. In the present work, the isothermal section of the Ni-Cr-Y ternary system at 900 °C is experimentally determined using the equilibrated alloys method combined with scanning electron microscopy and energy dispersive X-ray spectroscopy and X-ray diffractometry. Eight three-phase regions are confirmed and one three-phase region can be deduced in the isothermal section, and no new ternary compound is found.

[en] The 600 ^oC and 750 ^oC isothermal sections of the Zn-Bi-Ni ternary system have been determined experimentally using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and X-ray diffraction. Three three-phase regions exist in the isothermal section at 600 ^oC and 750 ^oC, respectively. The Ni-Zn phases are all in equilibrium with the liquid phase in these two isothermal sections. There is a four-phase equilibrated reaction occurred between 450 ^oC and 600 ^oC, namely β₁ + NiBi ↔ L + α-Ni, but more experimental works are needed for obtaining the accurate equilibrated reaction temperature. Experimental results show that Bi is almost insoluble in any Ni-Zn compounds and α-Ni. The solid solubility of Zn in the NiBi phase is also limited.