Phase Equilibria of the Co-Mo-Zr Ternary System at 1000 °C

The isothermal section of the Co-Mo-Zr ternary system at 1000 °C was investigated by using 29 alloys. The annealed alloys were examined by means of x-ray diffraction, optical microscopy, and electron probe microanalysis. It was confirmed that three ternary phases, λ₁ (Co_0.5-1.5Mo_1.5-0.5Zr, hP12-MgZn₂), ω (CoMoZr₄) and κ (CoMo₄Zr₉, hP28-Hf₉Mo₄B), exist in the Co-Mo-Zr ternary system at 1000 °C. And the experimental results also indicated that there are sixteen three-phase regions at 1000 °C. Thirteen of them were well determined in the present work: (1) (γCo)?+?Co₁₁Zr₂?+?Co₂₃Zr₆, (2) (γCo)?+?Co₂₃Zr₆?+?ε-Co₃Mo, (3) Co₂₃Zr₆?+?ε-Co₃Mo?+?μ-Co₇Mo₆, (4) (Mo)?+?μ-Co₇Mo₆?+?Co₂Zr, (5) (Mo)?+?Co₂Zr?+?λ₁, (6) (Mo)?+?Mo₂Zr?+?λ₁, (7) λ₁?+?Mo₂Zr?+?CoZr, (8) Co₂Zr?+?CoZr?+?λ₁, (9) Mo₂Zr?+?CoZr₂?+?ω, (10) κ?+?Mo₂Zr?+?ω, (11) CoZr₂?+?liquid?+?ω, (12) (βZr)?+?liquid?+?ω and (13) (βZr)?+?κ?+?ω. The homogeneity of λ₁ spans in the range of 28.66-50.77 at.% Co and 15.71-37.03 at.% Mo, and that for ω is within the range of 18.66-23.64 at.% Co and 8.53-14.68 at.% Mo. The homogeneity range for κ is from 8.09 at.% to 9.94 at.% Co and 23.13 at.% to 25.58 at.% Mo. The maximum solubility of Zr in μ-Co₇Mo₆ phase, Mo in Co₂Zr phase and Co in Mo₂Zr phase were determined to be 6.17, 11.27 and 9.14 at.%, respectively. While the solubility of Zr in ε-Co₃Mo and (γCo) phases, Mo in Co₁₁Zr₂ and CoZr phases were detected to be extremely small. According to this work, the Co₂₃Zr₆ phase contained 15.61 at.% Mo and 12.7 at.% Zr. In addition, the maximum solubility of Co and Zr in (Mo) phase and Mo in (γCo) phase were measured to be 3.50, 5.44 and 7.40 at.%, respectively.     

Experimental Determination of the Phase Equilibria of the La-Zn-Si System at 600 °C

The isothermal section at 600 °C of the La-Zn-Si system was established by using equilibrated alloys and the diffusion couple technique. Microstructural observation and phase identification were performed using optical microscopy, scanning electron microscopy with energy dispersive x-ray spectroscopy and a wave dispersive x-ray spectrometer, and x-ray powder diffraction. Seven ternary compounds were identified in this ternary system, and temporally designated as τ ₁, τ ₂, τ ₃, τ ₄, τ ₅, τ ₆ and τ ₇. Two previously reported ternary compounds, viz. τ ₁ and τ ₂, were found to exist at 600 °C. EDS analysis revealed that the τ ₁ phase contained Si from 2.4 to 6.1 at.% and La from 22.3 to 23.3 at.%. The compositional region of the τ ₂ single-phase ranged from 28.3 to 40.7 at.% for Si and from 31.5 to 33.1 at.% for La. Two new ternary phases, τ ₅ and τ ₆, were identified. The τ ₅ phase with the CeNiSi₂-type was determined to have a composition range of 36.9-39.2 at.% Si for about 24 at.% La. The τ ₆ phase with the ThCr₂Si₂-type was found to have a composition range of 18.9-19.7 at.% La and 27.4-30.6 at.% Si. The crystal structures of τ ₃, τ ₄, and τ ₇ were not determined. The solubility of Si in LaZn₁₃, LaZn₁₁, La₂Zn₁₇, La₃Zn₂₂, and LaZn₅ was negligible, and that of Si in LaZn₄, LaZn₂ and Zn in LaSi₂, La₃Si₂ was determined as 5.1, 2.3, 16.2 and 3.8 at.%, respectively.     

Phase Equilibria in the Cu-Sn-Sb Ternary System

The phase equilibria in the Cu-Sn-Sb ternary system were investigated by means of electron-probe microanalysis and x-ray diffraction. Firstly, ternary solubilities of η-Cu₆Sn₅, δ-Cu₄₁Sn₁₁, Cu₁₁Sb₃, ε-Cu₃Sb and η-Cu₂Sb, were less than 7 at.% Sb or Sn at 400 °C. Besides, an re-stabilized ternary solubility, Cu₆(Sn,Sb)₅, was detected with a homogeneity range of Cu: 52.9-53.3 at.%, Sn: 28.4-30.9 at.%, and Sb: 15.8-18.7 at.%. Its origin was traced back to high-temperature stabilization of the binary η-Cu₆Sn₅ phase. Thirdly, the metastable phase, Cu₁₁Sb₃, was observed at 400 °C in the Cu-Sn-Sb ternary system; On raising the temperature to 500 °C, the ε-Cu₃Sn phase still retained a large solubility for Sb, at?~?16 at.%, while the ε-Cu₃Sb was replaced by β-Cu₃Sb with a dual-cornered large homogeneity range. Similarly, a ternary homogeneity range of Cu: 83.8-84.9 at.%, Sn: 2.6-6.2 at.%, and Sb: 9-12.5 at.%, was found and deduced to be the high temperature stabilization phase of γ-Cu₁₁(Sb,Sn)₂ at 500 °C.     

Prospects of In-Situ <Emphasis Type="Italic">α</Emphasis>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> as an Inoculant in Aluminum: A Feasibility Study

In-situ α-Al₂O₃ was successfully synthesized and dispersed in Al alloy using B₂O₃ and ultrasonication-aided liquid mixing technique. Microstructure analysis identified α-Al₂O₃ as the most common phase in the composite master alloy, whereas AlB₁₂ was frequently observed and AlB₂ was rarely found in the alloy. Grain refinement analysis of selected Al alloys registered a transition of columnar to equiaxial grains of α-Al with the inoculation of the master alloy and ultrasonication treatment. Similarly, an improvement in the mechanical properties of A357 alloy was observed with the combination of inoculation and ultrasonication treatment.     

Characterization of Microstructure and Wear Resistance of PEO Coatings Containing Various Microparticles on Ti6Al4V Alloy

Titania-based composite coatings were prepared by plasma electrolytic oxidation (PEO) treatment of Ti6Al4V alloy in electrolyte with α-Al₂O₃, Cr₂O₃ or h-BN microparticles in suspension. The microstructure, composition of PEO composite coatings were analyzed by SEM, EDS and XRD. The wear resistance of composite ceramic coatings was studied by ball-on-disk wear test at ambient temperature and 300 °C. The results showed that the addition of microparticles accelerated the growth rate of PEO coating and changed the microstructure and composition of PEO coating. PEO coating was porous and mainly composed of rutile-TiO₂, anatase-TiO₂ and Al₂TiO₅. PEO/α-Al₂O₃ (Cr₂O₃ or h-BN) composite coating only had small micropores and appeared some α-Al₂O₃ (Cr₂O₃ or h-BN) phase. Besides, the addition of α-Al₂O₃ (Cr₂O₃ or h-BN) microparticles greatly improved the wear resistance of PEO coating. At ambient temperature, abrasive wear dominated the wear behavior of PEO coating, but abrasive wear and adhesive peel simultaneously happened at 300 °C. Whether at ambient temperature or 300 °C, PEO composite coating had better wear resistance than PEO coating. Besides, PEO/h-BN composite coating outperformed other composite coatings regardless of the temperature.     

Microstructure,Phase Occurrence,and Corrosion Behavior of As-Solidified and As-Annealed Al-Pd Alloys

In the present work, we studied the microstructure, phase constitution, and corrosion performance of Al₈₈Pd₁₂, Al₇₇Pd₂₃, Al₇₂Pd₂₈, and Al₆₇Pd₃₃ alloys (metal concentrations are given in at.%). The alloys were prepared by repeated arc melting of Al and Pd granules in argon atmosphere. The as-solidified samples were further annealed at 700 °C for 500 h. The microstructure and phase constitution of the as-solidified and as-annealed alloys were studied by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction. The alloys were found to consist of (Al), ε _n (~ Al₃Pd), and δ (Al₃Pd₂) in various fractions. The corrosion testing of the alloys was performed in aqueous NaCl (0.6 M) using a standard 3-electrode cell monitored by potentiostat. The corrosion current densities and corrosion potentials were determined by Tafel extrapolation. The corrosion potentials of the alloys were found between ? 763 and ? 841 mV versus Ag/AgCl. An active alloy dissolution has been observed, and it has been found that (Al) was excavated, whereas Al in ε _n was de-alloyed. The effects of bulk chemical composition, phase occurrence and microstructure on the corrosion behavior are evaluated. The local nobilities of ε _n and δ are discussed. Finally, the conclusions about the alloy’s corrosion resistance in saline solutions are provided.     

Phases and microstructures of high Zn-containing Al–Zn–Mg–Cu alloys

Phases and microstructures of three high Zncontaining Al–Zn–Mg–Cu alloys were investigated by means of thermodynamic calculation method, optica microscopy(OM), scanning electron microscopy(SEM)energy dispersive spectroscopy(EDS), X-ray diffraction(XRD), and differential scanning calorimetry(DSC) analysis. The results indicate that similar dendritic network morphologies are found in these three Al–Zn–Mg–Cu alloys. The as-cast 7056 aluminum alloy consists of aluminum solid solution, coarse Al/Mg(Cu, Zn, Al)_2 eutectic phases, and fine intermetallic compounds g(MgZn_2). Both of as-cast 7095 and 7136 aluminum alloys involve a(Al)eutectic Al/Mg(Cu, Zn, Al)_2, intermetallic g(MgZn_2), and h(Al_2Cu). During homogenization at 450 °C, fine g(MgZn_2) can dissolve into matrix absolutely. After homogenization at 450 °C for 24 h, Mg(Cu, Zn, Al)_2 phase in 7136 alloy transforms into S(Al_2Cu Mg) while no change is found in 7056 and 7095 alloys. The thermodynamic calculation can be used to predict the phases in high Zncontaining Al–Zn–Mg–Cu alloys.     

The Effect of Thermo-Mechanical Treatment on Structure of Ultrahigh Carbon PM Steel

The effects of thermo-mechanical treatment on selected properties related to the structure of Fe-0.85Mo-0.65i-1.4C powder metallurgy (PM) steel are reported. Three kinds of initial microstructure of specimens, i.e., pearlite + ferrite + cementite, martensite + retained austenite and α + spheroidized cementite were examined. Processing was carried out on a plastometer-dilatometer Bähr machine by compression cylindrical specimens at 775 °C at a strain rate of 0.001 s^?1. X-ray diffraction was carried out with symmetrical Bragg-Brentano and grazing incident angle methods on a D8-Advance diffractometer with filtered radiation of cobalt CoK _α . The following features were determined: texture, density of dislocations, density of vacancies, lattice parameter of Fe _α and mean size of crystallites. Significant differences in structure were observed, especially in quenched specimen, as a result of the thermo-mechanical treatment. Regardless of initial state of the specimens, the determined properties were on a similar level. Crystallite size was in the range 97-106 nm, crystallite texture (I{200}/I{110}) × 10 = 1.15-1.62 and density of vacancies I{110}/I{220} = 7.06-7.52.     

Movement of Multiple Markers in Cu/Zn Multiple Phase Diffusion Couples and Its Numerical Analysis

Movement of multiple markers (M-Ms) embedded in the Cu end member of a Cu/Zn multiple phases diffusion couple (M-couple) has been experimentally investigated at 623 K and the alignment of the M-Ms after diffusion anneal was reproduced by the numerical analysis that the authors have previously reported. Two intermediate phases, γ and ?, were found in the Cu/Zn M-couple. The M-Ms bent toward Zn side at Cu/γ phase interface and show almost a linear line in the γ phase. They again bent at γ/? interface toward Zn side. The Kirkendall marker position, X _k, locates in the ? phase layer. From this result, ratio, R = D _Zn/D _Cu, of the intrinsic diffusion coefficients with respect to the mole fixed frame of reference was determined to be about 46 at X _k. On the assumption of a constant value of R = 46 in the ? phase and appropriate constant values of R = 10-1000 in the γ phase, alignments of M-Ms after diffusion anneal were numerically reproduced. By fitting the alignment of M-Ms obtained numerically on the experimental result, the value R in γ phase is estimated to be very large value of 500.     

Effect of the structure and thickness of layers on the magnetic and magnetoresistive properties of <Emphasis Type="Italic">Py</Emphasis>/Co/Cu/Co nanocrystalline films

Py/Co₁/Cu/Co₂ films (Py is the Ni₆₃Co₂₅Fe₁₂ ternary permalloy) were produced by magnetron sputtering on glass substrates. The thicknesses of layers are d _Cu = 0.7–4 nm, \(d_{Co_2 } \) = 2–12 nm, and d _Py = 2–12 nm. The polar diagrams of the films with d _Cu = 1.2nm demonstrate a biaxial anisotropy, whereas the films with 2.0 ≤ d _Cu ≤ 3.0 nm are characterized by uniaxial anisotropy. The first maximum in the Δρ/ρ = f(d _Cu) curve is due to an antiferromagnetic coupling between the Py/Co₁ and Co₂ layers; the second maximum is due to the independent magnetization reversal of the Py/Co₁ soft magnetic bilayer and Co₂ hard magnetic layer. The magnetoresistance measured along the EA exhibits an almost twofold increase with increasing thickness of ferromagnetic layers. The coercive force was shown to decrease with increasing thickness of the Co₂ layer, whereas the magnetic anisotropy field is unchanged. The coercive force and induced magnetic anisotropy were estimated theoretically taking into account changes in the mean-square amplitude and roughness period with increasing thickness of the Co₂ layer. The results obtained agree with experimental data.     

The Effect of Synthesis Conditions on the Phase Composition and Structure of EuBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>6 + δ</Subscript> Samples

The composition and the structure of ceramic EuBa₂Cu₃O_{6 + δ} (Eu-123) oxide samples annealed in steps with varying processing conditions (in air or oxygen and argon atmosphere at a temperature of 940–960°С for 1–70 h with or without homogenization) were studied by the X-ray phase and chemical analysis, electron diffraction pattern analysis, elemental analysis, and high-resolution transmission electron microscopy. Regardless of the processing conditions, Eu-123 nanostructured oxide with a tetragonal or orthorhombic structure and domains 1–20 nm in size was obtained as a result of annealing. Nanostructuring of the samples, which was revealed by high-resolution electron microscopy, is attributed to their chemical nature: the presence of identical structural elements in members of the homologous Eu _n Ba _m Cu_{m + n}O _y series of oxides allows them to intergrow coherently and create an illusion of a single crystal. Just like any other member of the Eu _n Ba _m Cu_{m + n}O _y series, oxide Eu-123 is disproportionate depending on the annealing conditions to form other members of this series located on either side of the dominant oxide. Temperature T_c of the superconducting transition of each member of the series depends on the average oxidation state of copper \(\overline {Cu} \). At \(\overline {Cu} \) < 2, all members of the series have a tetragonal structure and do not exhibit superconducting properties. At \(\overline {Cu} \) = 2.28, five members of the Eu _n Ba _m Cu_{m + n}O _y series with matrices (Ba : Cu) 5 : 8, 3 : 5, 2 : 3, 5 : 7, and 3 : 4 exhibit superconducting properties with T_c = 82–90 K.     

High-power (Nd,Dy)–(Fe,Co)–B magnets with a low temperature coefficient of induction

High-power (Nd, Dy)–(Fe, Co)–B permanent magnets with a low temperature coefficient of induction (α) were prepared using advantages of strip casting and low-oxygen technologies. The microstructure and temperature dependences of magnetic properties have been studied on sintered (Nd_{1 – x} Dy _x )_13.9(Fe_{1 – y} Co _y )_79.8Cu_0.1Ga_0.1B_6.1 magnets with 0.20 ≤ x ≤ 0.25 and 0 ≤ y ≤ 0.20. The increase in y from 0 to 0.20 is accompanied by an increase in the Curie temperature from 327 to 492°C. This favors a decrease in the value of α from 0.099 to 0.060%/°C, respectively. Magnets with an oxygen content of no more than 2500 ppm which were prepared from the (Nd_0.75Dy_0.25)_13.9(Fe_0.85Co_0.15)_79.8Cu_0.1 Ga_0.1B_6.1 alloy, have the following hysteresis characteristics at 140°C: B _r ≥ 11.3 kG, H _c ≥ 8 kOe, and (BH)_max ≥ 30 MGOe; in this case, α ≤ |–0.07%/°С|.     

Electrical Conductivity and Dielectric Permittivity of γ-Irradiated Nanocomposites Based on Ultrahigh-Molecular-Weight Polyethylene Filled with α-SiO<Subscript>2</Subscript>

UHMWPE/SiO₂ composites were obtained from a homogeneous mixture of ultrahigh-molecular- weight polyethylene (UHMWPE) and silicon dioxide (α-SiO₂) by hot pressing. The temperature dependence (20–170°C) of their conductivities σdс prior to and after γ irradiation (D = 200 kGy), the effect of absorbed dose on the σ_dс value (dose dependence), the behavior of the function logσ_dc = f(T) under heating–cooling conditions, and the frequency dependences (25–106 Hz) of the real (ε') and imaginary (ε'') parts of the complex dielectric constant were studied. The logσ_dc = f(T) dependence was shown to have in both cases a complex pattern: “breaks” due to phase transitions were observed. With an increase in the concentration of α-SiO₂, the ε' and ε'' (tanδ) values in the matrix increased and the frequency dependences of these values corresponded to an exponential rule.     

Co-Cu alloys produced by mechanical alloying of powder precursors characterized by different contact surface and energy excess

Co-Cu alloys were prepared by mechanical alloying using different reaction mixtures (mechanical mixture of Co and Cu powders, composite powders (Co_{(100 ? y)}P_(y))_{100 ? x} /Cu _x with a crystalline core, and composite powders (Co_{(100 ? y)}P_(y))_{100 ? x} /Cu _x with an amorphous core). The use of a complex of structural and magnetostructural methods showed that these alloys are nonuniform nanocomposite materials consisting of two phases, namely, copper- and cobalt-based solid solutions. During the mechanical alloying of the composite powders, parameters that are sensitive to the short-range-order structure of both phases were found to be changed, namely, the lattice parameter in the Cu-based solid solution as determined from X-ray diffraction patterns, and the Bloch constant that is sensitive to the short-range order in the Co-based solid solution change. In the alloys prepared by mechanical alloying of composite powders with an amorphous core, the lattice parameter a and the Bloch constant B reach values corresponding to metastable Co_{100 ? x} Cu _x solid solutions in milling times of 1.5–2.0 h. These times are lower by 1–2 orders of magnitude than the typical times that are necessary for forming metastable Co-Cu solid solutions by standard methods of mechanical alloying from mixtures of powders.     

A Study of Tensile Flow and Work-Hardening Behavior of Alloy 617

The simple power relationship σ?=?Κε _p ⁿ satisfactorily expresses the tensile flow behavior of many metals and alloys in their uniform plastic strain regime. However, many FCC materials with low stacking fault energy have opposed such power law relationship. Alloy 617, an age-hardenable Ni-based superalloy is also observed not to obey the simple power law relationship neither in its solution-treated nor in its aged conditions. Various flow relationships were used to obtain the best fit for the tensile data, and different relationships were identified for the different aged conditions. The work-hardening rate (θ) demonstrates three distinct regions for all aged conditions, and there is an obvious change in the trend of θ versus σ. In the initial portion, θ decreases rapidly followed by a gradual increase in the second stage and again a decrease in its third stage is perceived in the Alloy 617. These three-stage characteristics are attributed to a commonly known precipitate, γ′: Ni₃(Ti, Al) which evolves during aging treatment and well recognized under transmission electron microscopy (TEM) observation. TEM results also reveal a slight degree of coarsening in γ′ over aging. The tensile flow and the work-hardening behavior are well correlated with other microstructural evolution during the aging treatments.     

Isothermal Section of Er-Ag-Sn System at 873 K

The isothermal section of the Er-Ag-Sn system at 873 K was constructed with the use of scanning electron microscopy, energy-dispersive x-ray microanalysis and x-ray powder diffraction. Two ternary compounds were confirmed at this temperature: ErAgSn (LiGaGe structure type, P6₃mc, Z = 2, a = 4.6595(2) Å, c = 7.2872(3) Å) and non-stoichiometric phase ErAg_1?xSn_2+x (Cu₃Au structure type, Pm-3m, Z = 1). For the last one homogeneity range was established (0.08 < x < 0.24) and lattice parameters were determined (a = 4.5007(4), 4.5040(2), 4.5107(1), 4.5412(1) Å for the compositions Er_25.4Ag_23.4Sn_51.2, Er_25.7Ag_23.0Sn_51.3, Er_25.7Ag_21.7Sn_52.6, Er_25.2Ag_18.6Sn_56.2 (at.%) respectively). Melting point of the phase Er_25.7Ag_21.7Sn_52.6 (at.%) was determined to be 1199 K by differential thermal analysis.     

Influence of Nb on microstructure and mechanical properties of Ti-Sn ultrafine eutectic alloy

In this study, A series of the high strength (T₈₂Sn₁₈)_100-xNb_x (x=0, 1, 3, 5, and 9 at%) ultrafine eutectic alloys with large plasticity are developed by suction casting method. The Ti₈₂Sn₁₈ binary eutectic alloy consists of a mixture of a hcp Ti₃Sn and a α-Ti phases having the plate-like lamellar type duplex structure with micro scaled eutectic colony. From the (T₈₂Sn₁₈)₉₇Nb₃, the alloy display structural heterogeneous distribution of ultrafine-scaled phases composed of β-Ti(Nb) solid solution surrounded by alternating plate-like shaped Ti₃Sn and α-Ti phases. With increasing Nb content, the volume fraction of β-Ti is continuously increased, which induced improving mechanical properties both strength and plasticity. Especially, (Ti₈₂Sn₁₈)₉₁Nb₉ alloy has the outstanding combination of the high strength (σ _y ≈1.1 GPa) and large plasticity (ε _p ≈36%) at room temperature.     

Fabrication and Characterization of Plasma-Sprayed Carbon-Fiber-Reinforced Aluminum Composites

Carbon fiber (C_f)/Al specimens were fabricated by plasma-spraying aluminum powder on unidirectional carbon fiber bundles (CFBs) layer by layer, followed by a densification heat treatment process. The microstructure and chemical composition of the C_f/Al composites were examined by scanning electron microscopy and energy-dispersive spectrometry. The CFBs were completely enveloped by aluminum matrix, and the peripheral regions of the CFBs were wetted by aluminum. In the wetted region, no significant Al₄C₃ reaction layer was found at the interface between the carbon fibers and aluminum matrix. The mechanical properties of the C_f/Al specimens were evaluated. When the carbon fiber volume fraction (CFVF) was 9.2%, the ultimate tensile strength (UTS) of the C_f/Al composites reached 138.3 MPa with elongation of 4.7%, 2.2 times the UTS of the Al matrix (i.e., 63 MPa). This strength ratio (between the UTS of C_f/Al and the Al matrix) is higher than for most C_f/Al composites fabricated by the commonly used method of liquid-based processing at the same CFVF level.     

Pseudo-gap and the nonlinearity of the magnetization of textured polycrystals of YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7 − <Emphasis Type="Italic">x</Emphasis></Subscript> above the temperature of transition into the superconducting state

Temperature dependences of the third and other higher harmonics of the magnetization of textured polycrystalline samples of YBa₂Cu₃O_{7 ? x} have been studied in the temperature range of 77–120 K. It has been revealed that the nonlinearity of magnetization of YBa₂Cu₃O_{7 ? x} is observed up to temperatures that considerably exceed the temperature of transition into the superconducting state. The observed nonlinearity of magnetization of YBa₂Cu₃O_{7 ? x} is ascribed to the appearance of a pseudogap state at T ～ 102 K in this compound. A method of determining the temperature of the appearance of the pseudogap T * in the high-T _c compounds is suggested, which is based on the measurement of magnetization harmonics.     

Investigation of Fe content in Cu–Al–Ni Shape Memory Alloys

Polycrystalline Cu–Al–Ni–Fe-based shape memory alloys with different chemical composition were produced in an arc-melting furnace under an argon atmosphere. Homogenized and aged specimens were prepared for multiple analyses. The temperatures of reversible martensitic transformations, namely A_s, A_f, M_s, M_f, A_max and ΔH enthalpy values were determined by a DSC device. The phase transition analysis from the room temperature to 850°C was undertaken by DTA. To characterize the lattice structure, an XRD analysis was conducted, the results of which were confirmed by microstructure images obtained from optical microscope observations.