Effect Of Ternary Additions Research Articles

The effect of ternary additions on the structural and mechanical properties of B2 phase FeCo magnetic alloy

FeCo alloy constitutes an important class of soft-magnetic materials with a wide range of technological applications. This class of materials offers exceptional magnetic properties due to their rare combination of good properties like high mechanical strength, and high saturation magnetization. Fortunately, this alloy has good magnetic properties, but shows low levels of ductility at room temperature. This study intends to use density functional theory (DFT), to understand how ternary alloying with Pd and Mn can improve the ductility of B2 FeCo system. We probe the relationship between stability and composition of the ternary Fe50Co50−xMx (M = Pd, Mn) with different M content. Furthermore, the study also investigates how ternary alloying affects the stability of the B2 FeCo alloy. There is a significant enhancement of ductility with Mn addition than Pd ternary addition. It is noteworthy that small composition of Pd (< 10 at.%) does not compromise the valuable properties of FeCo. The findings suggest that Fe50Co50−xMx alloys can be used for the future development of magnetic components with good strength.Graphical abstractThe effect of ternary additions on the structural and mechanical properties of B2 phase FeCo magnetic alloy.

The effect of ternary additions on the hyperfine interaction parameters at Fe nuclei in the Fe50Al50 compound: First-principles calculations

First-principles calculations using the linear augmented plane wave method (LAPW) within the framework of the density functional theory were performed to investigate the effect of the substitution of Fe atoms by transition elements (4d-T = Tc, Ru, Rh; 5d-T = Re, Os, Ir), in the concentration of 1.85 at.%, on the hyperfine interaction parameters at Fe nuclei in the Fe50Al50 compound. The results revealed that the ternary alloying additions lead to variations in the hyperfine interactions. Significant variations of the magnetic hyperfine field (Hhf) and of the isomer shift (IS) occur for Fe atoms nearest neighbors (nn) to T atom and depend upon the number of outer shell electrons (Ne) of the T atom. The larger changes in the Hhf of Fe nn were observed for 4d-T and 5d-T atoms with Ne = 7 and 8, while the changes of the IS arise by additions of T atoms with Ne = 8 and 9. The calculations results of the electric field gradient have shown variations that reflect a pronounced redistribution of charge over all Fe sites of the lattice. All the results point out a significant disturbance of the spatial distribution of the valence charge around Fe nuclei.

Effects of ternary metal additions on corrosion of spark plasma sintered Ni-Fe alloys in H2SO4 and NaCl

Effect of ternary additions on electrochemical behavior of Ni-Fe binary alloys developed by Spark Plasma Sintering (SPS) were investigated and reported. All specimens revealed common passivity behavior in H 2 SO 4 . Both binary and ternary alloys did not reveal passivity region under saline conditions. The alloys have lower corrosion rates in NaCl than in H 2 SO 4 . Binary Ni 50 Fe 50 alloy is characterized by large pits in H 2 SO 4 and homogeneous corrosion on surface in NaCl. Ni 50 Fe 40 Ta 10 shows better passivity in 1 M H 2 SO 4 and Ni 50 Fe 40 Al 10 has the lowest corrosion rate in 3.5 wt.% NaCl. KEY WORDS : Spark plasma sintering, Corrosion, Ni-Fe based alloy, Ternary alloys, Powder metallurgy Bull. Chem. Soc. Ethiop. 2018 , 32(2), 337-349. DOI: https://dx.doi.org/10.4314/bcse.v32i2.12

Advances in Ti-Based Systems as High Temperature Shape Memory Alloys

In this study, we investigate the effect of ternary addition on the structural, mechanical properties and temperature dependence of Ti-based as potential shape memory alloys using molecular dynamics approach. We found that binary Ti-Pt alloys exhibit shape memory properties and display possible martensitic transformation from B2 to B19 phases. Partial addition with Zr, Co, Pd, Ir showed preferential ternary high temperature shape memory alloys formation of 6.25 at. % X composition (Ti-Pt-X). We found that the equilibrium lattice constants are in better agreement with the available experimental values. The heats of formation and elastic properties reveal possible composition and phases at temperature above 900 K with good shape memory properties. Their structures were confirmed using the X-ray diffraction patterns at different temperatures.

Effect of Ternary Additions X (Co, Rh, Ir) on Electronic Properties of TiPd Shape Memory Alloy: An ab-initio Study

Effect of Ternary Additions X (Co, Rh, Ir) on Electronic Properties of TiPd Shape Memory Alloy: An ab-initio Study

Sintering behavior and effect of ternary additions on the microstructure and mechanical properties of Ni–Fe-based alloy

ABSTRACTThe sintering behavior and effect of ternary additions on the microstructure and mechanical properties of Ni–Fe-based alloy were investigated, with the ternary additions Al, Co, Cr, Mo, Ta, and Ti. The effect of the different ternary additions was more obvious when comparing Ni40Fe10X (X = Al, Ti) and the rest of the alloys, with the former having better density and hardness than the latter. Sintered densities close to theoretical (≥98%), excluding Ni40Fe10Mo, were achieved. Interestingly, the visible porosity regions in all the samples were very small in agreement of the high sintered densities observed. The shrinkage rate was similar for all the alloys, and three peaks were observed, the first two peaks merged, and overall all the peaks were indicative of the phenomena responsible for good densification. The hardness measurement revealed that samples with poor homogeneity and those with clusters of ternary element addition in the microstructure had no hardness improvement compared to the base binary alloy. For alloys with Al, Cr, and Ti, fracture surface SEM morphology revealed the intergranular fracture of the grains and the ductile tearing of the binding phase, typical dimple structure of a ductile material; therefore, the mechanical properties of these samples are improved, while the rest of the alloys were characterized with peeling of very fine spherical particles and varying grain size and consequently compromising its mechanical properties.

Effects of ternary additions on the microstructure and thermal stability of directionally-solidified MoSi2/Mo5Si3 eutectic composites

Effects of ternary additions on the microstructure and thermal stability of directionally-solidified MoSi2/Mo5Si3 eutectic composites have been studied for twelve different elements (Ti, V, Cr, Fe, Co, Ni, Nb, Ta, W, Ir, B and C) paying special attention to the variation of lattice misfits and interface segregation behavior with ternary additions. Among six elements (type-1: Ti, V, Cr, Nb, Ta and W) with a relatively high solubility in MoSi2 and Mo5Si3, Ta and W are found to be beneficial to microstructure refinement. All other six ternary elements (type-2: Fe, Co, Ni, Ir, B and C) with a negligibly low solubility in MoSi2 and Mo5Si3 exhibit a strong tendency to segregate on MoSi2/Mo5Si3 interfaces, resulting in both microstructure refinement and the modification of the interface morphology.

Effect of Fe ternary addition on ductility of NiAl intermetallic alloy

Mechanical and physical properties of NiAl intermetallics with B2 structure are of great technological interest for high temperature applications. However, NiAl is brittle at low temperature, which limits the practical applications in industry. Recently, it was reported that an addition of Fe on the Al sublattice results in an unusual solid softening effect in NiAl. The mechanism of the solid softening effect remains unclear. In this paper, the solid softening effects of ternary addition of Fe in NiAl were investigated by both experimental work and theoretical calculations. The results show that addition of 6–10 at.% Fe on the Al sublattice enhances the ductility of NiAl markedly. The compressive plasticity increases from 0.75 % in Ni60Al40 to 19.5 % in Ni50Al40Fe10 and the compressive fracture strength from 900 MPa to 1180 MPa. In contrast, the yield strength decreases from 873 MPa in Ni60Al40 to 473 MPa in Ni50Al40Fe10. Furthermore, elastic and slip properties of Ni(Al,Fe) intermetallic alloys were calculated by first-principles and the solid softening effect in NiAl was discussed with the theoretical results.

Effect of chromium ternary additions on the ordering behaviour in Fe–28at.% Al alloy

The ordering iron aluminide alloys such as Fe 3 Al and FeAl which exhibit D0 3 and B2 ordered structures have received considerable attention for their unique properties and wide range of applications. It is well-known that the mechanical properties are a function of the order degree of the materials; therefore, it is important to know the effect of ternary additions on the ordering behaviour of these materials for improving the mechanical properties by alloying elements. The aim of the present study was to investigate the chromium addition effect on B2 → D0 3 order transition utilizing differential scanning calorimetry (DSC), dilatometric analysis and microhardeness measurements and to estimate the activation energy and the Avrami exponent n of D0 3 phase. The thermal analysis and the determination of kinetics parameters of Fe–28 at.% Al–2 at.% Cr and Fe–28 at.% Al–5 at.% Cr alloys have shown that the effects of chromium addition are to stabilize the B2 ordered phase and to make the B2 → D0 3 transition slower than in the binary Fe–28 at.% Al alloy.

Effect of Ternary Additions on the Stability of Ordered Phases in Ni-Mo Alloys—Transmission Electron Microscopy Results and First Principles Calculations

The ordering behavior of a Ni-Mo alloy in the presence of ternary additives X (X = Al, Cr, Mn, V) has been studied using transmission electron microscopy (TEM) as well as first-principles calculations using the tight-binding–linear muffin tin orbital (TB-LMTO) method. The sequence of ordering transformations in binary Ni-Mo alloys has been shown earlier to be controlled by a competition between several fcc-based superlattices, viz. Ni2Mo (Pt2Mo type), Ni3Mo (D022), Ni4Mo (D1a), and the so-called short-range ordered (SRO) structure characterized by the presence of {1½0} reflections. These ternary additives have been observed to stabilize the Ni3Mo (D022) phase compared to the Ni2Mo + Ni4Mo phase mixture, leading to a sequence of transformation different from that obtained in binary alloys. The calculated energies of formation were observed to conform to the experimentally observed stability hierarchy in these binary intermetallics and their ternary analogues. The third element stabilizes the D022 structure by contributing to the covalent component of bonding in these compounds.

Effects of ternary additions on martensitic transformation of TiAu

The effects of ternary element additions on martensitic transformation start temperature ( M s) and factors for controlling M s were investigated for the Ti–Au alloy systems. The ternary elements X selected were Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir and Pt, which substitute for the Au sites. The concentration of ternary elements was chosen to be 1 and 3 mol%. The alloys of Ti 50(Au, X) 50 were fabricated by Ar arc-melting followed by a homogenization at 1173 K for 3.6 ks. M s was measured by differential scanning calorimetry. It was found that the apparent phases at room temperature identified by θ − 2 θ X-ray diffraction were B19 regardless of ternary additions. The correlations between M s or the change in M s by adding 1 mol% of X (Δ M s) are discussed in terms of electron atom ratio ( e/a), valence electron number ( N e), Mendeleev number ( N M) and lattice parameter ratio between c- and b-axes ( c/b) of B19 martensite phase. It was found that M s decreases linearly with increasing amount of ternary additions and that Δ M s is −40 K/mol% for Ru and −5 K/mol% for Cu, for example. Besides, the dependence of M s on the above factors is presented and linear correlations are obtained.

Effect of ternary additions on the structure and properties of coatings produced by a high aluminum galvanizing bath

A zinc-aluminum eutectoid galvanized steel has been developed. The basic composition of the bath is selected close to the eutectoid point in the binary Zn—Al system, together with ternary additions in the form of bismuth, rare-earths and silicon.

Effect of ternary Al, Ni additions on hydrogen absorption behaviour of Ti–45Nb alloys

Abstract The present study investigates the hydrogen absorption behaviour of a binary Ti–45Nb alloy and the effect of ternary additions of Ni and Al on the pressure–composition–temperature (i.e. p – c – T ) behaviour of this alloy. It is found that at a given temperature and partial pressure, the Al-containing alloy has the lowest hydrogen content, followed by the Ni-containing alloy, and that the binary alloy exhibits maximum hydrogen absorption capacity. A comparison of the enthalpy of solution as a function of hydrogen content of the three alloys shows that the enthalpy minimum for the Al-containing alloy occurs at the lowest hydrogen content, followed by that for the binary alloy, and the enthalpy minimum for the Ni-containing alloy occurs at the highest hydrogen content. Enthalpy of solution at infinite dilution of hydrogen shows a linear dependence on the lattice parameter of the host alloys. X-ray analysis of the hydrogen containing samples reveals suppression of the α-phase and the Ti 2 Ni-phase in the presence of hydrogen.

Effects of ternary additions on the thermoelastic martensitic transformation of NiAl

Nickel-rich β-NiAl alloys, which are potential materials for high-temperature shape-memory alloys, show a thermoelastic martensitic transformation, which produces their shape memory effect. However, the transformation to Ni 5 Al 3 phase during heating of NiAl martensite can interrupt the reversible martensitic transformation; consequently, the shape memory effect in NiAl martensite might not appear after heating. The phase transformation process in binary Ni-(34 to 37)Al martensite was investigated by differential thermal analysis (DTA) method, and we found that the condition of reversible martensitic transformation was not the β → Ni 5 Al 3 transformation, but rather the M → Ni 5 Al 3 transformation occurring at 250 °C to 300 °C. Therefore, the transformation temperature of M → Ni 5 Al 3 determined the highest operating temperature for the shape memory effect. For verifying the critical temperature, the phase transformation process was investigated for eight ternary Ni-33Al-X alloys (X = Cu, Co, Fe, Mn, Cr, Ti, Si, and Nb). Only Ti, Si, and Nb additions were found to be effective in dropping the M s temperature, and they facilitated the shape memory effect in Ni-33Al-X alloys. In particular, the addition of Si and Nb raised the transformation temperature of M → Ni 5 Al 3 , a potentially beneficial effect for shape memory at higher temperatures.

Effect of ternary addition and γ-irradiation on the characteristics of rapidly solidified Pb-base alloys

The properties of a series of rapidly solidified Pb-Sb 3 -Sn x alloys ( x =0-2.5 r wt.%) irradiated with n -rays were studied. Variations in the internal friction, Q m 1 , thermal diffusivity D th and dynamic Young's modulus Y were traced before and after irradiation by applying the resonance technique. Variations of specific heat C p were obtained from DTA thermograms. Structure parameters were obtained from the X-rays diffraction patterns. A marked change in the behaviour of the measured parameters was observed at 1.5 r wt.% Sn addition. Besides, irradiation induced defects increased the level of the measured hardening parameters.

Mechanical properties of Cr, Mn, Fe, Co, and Ni modified titanium trialuminides

To increase gas turbine efficiency, new high-temperature-resistant and lightweight materials are needed. Titanium trialuminides are an interesting option, but they are currently too brittle at room temperature to be used as turbine blades. Brittleness of TiAl3 can be reduced by alloying with several transition metal elements. The effect of ternary additions of Cr, Mn, Fe, Co, or Ni at various stoichiometries (3 to 9 at.%) to the intermetallic TiAl3 is studied by metallography, X-ray diffraction and three-point-bend testing. These methods indicate that the 6 at.% Cr or Co additions give the highest flexural strength with only a small trade-off in failure strain when compared to the 9 at.% additions of chromium and manganese.

Effect of Ternary Addition on Characteristics of Pb-Sn Base Alloys

A study of the microaddition dependence of the structural, mechanical and electrical characteristics of lead-5wt.% Sn alloy prepared by melt spinning and/or the conventional method was carried out using X-ray diffraction, dynamic resonance technique, hardness and resistivity measurements. The conventional method produced more crystalline structure than that of the melt spun. The thermal diffusivity, hardness and resistivity values were found to be higher for PbSn samples prepared by the conventional method than those of the melt spun PbSn samples, while the value of the internal friction was higher for the melt-spun alloy samples. This may be due to the creation of defects by the rolling process used during the preparation of the cold rolled sheets. The dynamic Young’s modulus was nearly of the same order for both the rapidly solidified and the cold rolled alloys. The results were explained in terms of the dislocation theory, the effect of quenching rate on the produced density fluctuations in composition and the modes of interaction of crystal lattice defects.

The effect of ternary addition on the formation and the thermal stability of L1 2 Al 3Zr alloy with nanocrystalline structure by mechanical alloying

We have tried to produce nanocrystalline L1 1 Al+25 at.% Zr+12.5 at.% M (M=Cu, Ni, Mn) alloys by planetary ball milling of elemental powders. Systematic studies on ternary addition on the formation and the thermal stability of metastable L1 2 phase are also given in this study. L1 2 Al 3Zr alloy was effectively prepared by mechanical alloying of elemental powders of Al and Zr for 3 h. In the case of ternary addition the L1 2 phase was formed after 6-h milling for Cu and 3-h milling for Ni. In Mn addition, the L1 2 phase was formed after 3 h and transformed into an amorphous phase after 6 h. The as-milled L1 2 Al 3Zr and L1 2 Al 5Zr 2Cu alloy powder had nanocrystalline structures with grain sizes less than 10 nm. L1 2 Al 3Zr alloy transformed into stable D0 23 phase at 625°C. L1 2 phase has been stabilized significantly by ternary addition up to over 900°C for Cu and 850°C for Ni, respectively. Amorphous Mn added to Al 3Zr alloy crystallized to L1 2 phase at 770°C and the crystallized L1 2 phase was stable up to over 900°C. The nanocrystalline structure was maintained after 20-min heat treatment at 900°C.

Potential of IrAl base alloys as ultrahigh-temperature smart coatings

For developing ultrahigh-temperature oxidation-resistant coatings, phase constitution and stability, fabrication methods, mechanical properties, thermal expansion and oxidation behavior are discussed for B2 IrAl alloys. Effects of ternary additions (Ni, Co and Fe) on oxidation behavior are also described. For practical use of ultrahigh-temperature coatings, an effective oxygen diffusion barrier (ODB) is required for the heart of multilayered ultrahigh-temperature coatings and Ir has promise to be ODB. A problem in using Ir is a formation of gaseous oxide, IrO3, over 1395K. This can be overcome by alloying with Al. Recently we have found that, by oxidation, IrAl-base alloys form smart and self-healing multifunctional layered structures composed of (1) continuous Ir layer as ODB and (2) continuous Al2O3 layer to protect ODB. In this paper, several characteristics of IrAl alloys are described and potential of IrAl as smart oxidation resistant coatings is discussed.

Effects of ternary additions on the deformation behavior of single crystals of MoSi2

ABSTRACTEffects of ternary additions on the deformation behavior of single crystals of MoSi2 with the hard [001] and soft [0 15 1] orientations have been investigated in compression and compression creep. The alloying elements studied include V, Cr, Nb and Al that form a C40 disilicide with Si and W and Re that form a C11b disilicide with Si. The addition of Al is found to decrease the yield strength of MoSi2 at all temperatures while the additions of V, Cr and Nb are found to decrease the yield strength at low temperatures and to increase the yield strength at high temperatures. In contrast, the additions of W and Re are found to increase the yield strength at all temperatures. The creep strain rate for the [001] orientation is significantly lower than that for the [0 15 1] orientation. The creep strain rate for both orientations is significantly improved by alloying with ternary elements such as Re and Nb.