Kinetics of crystallization process for bulk glass forming Zr-base alloys

The crystallization kinetics of Zr₆₅Ni₁₀Cu_17.5Al_7.5 (alloy I) and Zr_52.5Ni_14.6Cu_17.9Al₁₀Ti₅ (alloy II) are investigated. Two-stage crystallization takes place during continuous heating of the glassy alloy I, resulting in the transformation of the glass to the metastable α-Zr-solid solution and Zr-base quasicrystals with an activation energy of 309 KJ/mol in the first-stage and the formation of Zr₂Cu compound and the stable α-Zr-solid solution with an activation energy of 227 KJ/mol in the second-stage. For alloy II, one-stage crystallization with an activation energy of 333 KJ/mol occurs during continuous heating of the glass, resulting in the formation of Zr₃Al and α-(Zr,Ti)-solid solution. Based on the DSC data and calculations, both the alloys go through with three stages of crystallization mechanism during isothermal annealing, i.e. (1) surface nucleation and growth, (2) three-dimensional nucleation and growth, and (3) crystal growth. The TEM observation on Zr_52.5Ni_14.6Cu_17.9Al₁₀Ti₅ alloy is in good agreement with the calculations.     

Corrosion behavior of Ni-based amorphous alloys and their crystalline counterparts

In this paper, we report the corrosion behavior of Ni₅₉Zr₂₀Ti₁₆Si₂Sn₃ and Ni₅₃Nb₂₀Ti₁₀Zr₈Co₆Cu₃ (at.%) amorphous alloys with glass forming ability (GFA) of ∼3 mm, and their crystalline counterparts in severe corrosive environment of 1 M HCl aqueous solution. From the results of polarization curves and X-ray photoelectron spectroscopy (XPS), it was found that the corrosion behavior in Ni-based amorphous alloys is very sensitive to the compositions and the structural homogeneity is favorable for their corrosion-resistance in 1 M HCl aqueous solution.     

Deuterium Storage of Ti39Zr38Ni17Pd6 Icosahedral Quasi- crystal

Ti-Zr-Ni基二十面体准晶是一类特殊的储氢材料,在氢能和核聚变能领域具有较强应用前景。采用XRD、TEM、XPS技术和气固反应系统研究了Ti39Zr38Ni17Pd6二十面体准晶的储氘性能。该合金室温下的饱和吸氘浓度接近 11 mmol·D2/g·M (D2指氘分子,M指金属),超过Zr2Fe和ZrCo 2种合金。在吸放氘循环过程中,没有发现该合金发生相转变。饱和吸氘使得准晶格膨胀了6.37%,并使得Ti与Zr的结合能上升0.2和0.6 eV,反映出氢原子在这种材料中的占位更靠近这2种金属原子。放氘结果显示该合金具有可能较低的坪台压力,350 ℃左右低于1 kPa,这意味着氘原子在该合金中比在ZrCo合金中具有更高的稳定性。以上结果表明,这种准晶有可能替代Zr2Fe和ZrCo合金而在核聚变能领域得到应用。     

Effects of electrochemical hydrogenation of Zr-based alloys with high glass-forming ability

Zr–(Ti)–Cu–Al–Ni metallic glasses exhibit a high thermal stability corresponding to a wide undercooled liquid region. Depending on their composition, the formation of metastable intermediate phases, e.g. a quasicrystalline phase is possible. The combination of early and late transition metals makes these alloys very interesting regarding their interaction with hydrogen. Amorphous Zr₅₅Cu₃₀Al₁₀Ni₅, Zr₆₅Cu_17.5Al_7.5Ni₁₀ and Zr₅₉Ti₃Cu₂₀Al₁₀Ni₈ ribbons were prepared by melt spinning and their microstructure and thermal behaviour was checked by X-ray diffraction, transmission electron microscopy and differential scanning calorimetry. The cathodic reactivity of alloy samples at different microstructural states and after pre-etching in 1 vol.-% HF was investigated in 0.1 M NaOH by applying potentiodynamic polarisation techniques. Galvanostatically hydrogenated samples were characterised by XRD, DSC, TEM and thermal desorption analysis (TDA). For amorphous Zr₅₉Ti₃Cu₂₀Al₁₀Ni₈ samples an increase in electrochemical surface capacity by two orders of magnitude is observed after pre-etching. Compared to the quasicrystalline and crystalline alloy, the hydrogen reduction takes place at significantly lower overpotentials. Zr-based alloys cathodically absorb hydrogen up to H/M=1.65 while keeping the amorphous structure. Already small amounts of hydrogen cause a significant decrease of the thermal stability and changes in the crystallisation sequence. The hydrogen desorption is a two-stage process: (T<623 K) hydrogen desorption from high interstitial-site energy levels and (T>623 K) zirconium hydride formation and subsequent transformation under hydrogen effusion. Hydrogen suppresses the oxygen-triggered formation of metastable phases upon heating and supports primary copper segregation. At very high H/M ratios, severe zirconium hydride formation causes the crystallisation of new compounds.     

Microwave-induced heating and sintering of metallic glasses

Metallic glasses exhibit low viscosity in a temperature range between the glass-transition and crystallization temperature which allows successful sintering of glassy powders. Microwave heating being a volumetric heating has significant advantages over conventional heating in materials processing, such as substantial energy savings, rapid heating rates and process cleanness. In the present study, we investigate the stability of the Fe₇₃Si₇B₁₇Nb₃, Fe₆₅Co₁₀Ga₅P₁₂C₄B₄, Ni_52.5Zr₁₅Nb₁₀Ti₁₅Pt_7.5, Ni₆₀Nb₂₀Ti₁₅Zr₅, Zr₅₅Cu₃₀Al₁₀Ni₅ and Ti_47.5Zr₁₀Cu₃₀Pd_7.5Sn₅ glassy powders and formation of the porous bulk metallic glassy samples by microwave heating in a single-mode cavity with separated electric (E) and magnetic (H) field maxima in an inert atmosphere. The Fe₇₃Si₇B₁₇Nb₃ and Fe₆₅Co₁₀Ga₅P₁₂C₄B₄ alloys crystallized upon MW heating in both E- and H-field maxima forming a nanostructure. The Ni_52.5Zr₁₅Nb₁₀Ti₁₅Pt_7.5 and Zr₅₅Cu₃₀Al₁₀Ni₅ alloys were heated well in H-field and were not heated well enough in E-field. In case of Ni_52.5Zr₁₅Nb₁₀Ti₁₅Pt_7.5 and Ni₆₀Nb₂₀Ti₁₅Zr₅ alloys sintered samples were obtained.     

Effects of a small amount of Si or Ge addition on stability and hydrogen-induced internal friction of Ti34Zr11Cu47Ni8 glassy alloys

Effects of a small amount of Si or Ge addition on stability and hydrogen-induced internal friction behavior of Ti₃₄Zr₁₁Cu₄₇Ni₈ glassy alloys have been investigated by X-ray diffraction, thermal analysis and temperature dependence of internal friction. It is found that the addition of 1 at.% Si, 2 at.% Si or 1 at.% Ge is effective to stabilize the glassy state and that Si is more effective than Ge. The peak internal friction of the single glassy phase alloy increases with increasing hydrogen content below about 20 at.% H. It is found that (Ti₃₄Zr₁₁Cu₄₇Ni₈)₉₉Si₁ glassy alloys have lower peak internal friction than the Ti₃₄Zr₁₁Cu₄₇Ni₈ glassy alloys, while (Ti₃₄Zr₁₁Cu₄₇Ni₈)₉₈Si₂ and (Ti₃₄Zr₁₁Cu₄₇Ni₈)₉₉Ge₁ glassy alloys have much higher peak internal friction. It should be noted that a (Ti₃₄Zr₁₁Cu₄₇Ni₈)₉₈Si₂ glassy alloy containing 14.4 at.% H shows high internal friction, Q⁻¹ of about 4 × 10⁻². The peak temperature of the single glassy phase alloys decreases with increasing hydrogen content below about 20 at.%. It should be noted that the addition of an extremely small amount of Si is effective to increase the peak temperature of the single glassy phase alloys. The relationship between the tensile strength and specific damping capacity indicates that the hydrogenated (Ti₃₄Zr₁₁Cu₄₇Ni₈)₉₈Si₂ glassy alloys have almost the same potential for a damping material as crystalline Mn–Cu–Al and Cu–Al–Ni alloys and hydrogenated Zr–Cu–Al glassy alloys.     

Hydrogen and Zr-based metallic glasses: Gas/solid absorption process and structure evolution

The absorption of hydrogen by means of gas-solid reaction and its consequence on the structure have been studied for fully amorphous alloys as well as quasicrystals/glassy composite alloys based on the composition Zr₅₉Ti₃Cu₂₀Al₁₀Ni₈. The process of hydrogen absorption has been performed and monitored under 20 bar of H₂ using high pressure-differential scanning calorimetry (HP-DSC). The structure evolution of the samples has been followed by X-ray diffractometry (XRD). Results show that the nature of the surface oxide layer strongly affects the process of hydrogen absorption, especially its starting temperature. The structure evolves nevertheless along the same basic sequence, regardless of the sample: (i) the alloys keep a global amorphous structure up to roughly H/M = 0.8 and T = 350 °C; (ii) then ZrH₂ and at higher temperature Cu₂AlZr are formed. The stability of the glass is weakened and the formation of quasicrystals is inhibited under 20 bar of H₂. An heterogeneous distribution of hydrogen atoms inside the amorphous matrix has been inferred from the results.     

Glass-forming ability and stability of ternary Ni-early transition metal (Ti/Zr/Hf) alloys

Four Ni-bearing Ti, Zr and Hf ternary alloys of nominal composition Zr_41.5Ti_41.5Ni₁₇, Zr₂₅Ti₂₅Ni₅₀, Zr_41.5Hf_41.5Ni₁₇ and Ti_41.5Hf_41.5Ni₁₇ were rapidly solidified in order to produce ribbons. The Zr–Ti–Ni and Ti–Hf–Ni alloys become amorphous, whereas the Zr–Hf–Ni alloy shows precipitation of a cubic phase. The devitrification of all three alloys was followed and the relative tendency to form nanoquasicrystals and cF96 phases analysed. The relative glass-forming ability of the alloys can be explained by taking into account their atomic size difference. Addition of Ni often leads to quasicrystallisation or quasicrystal-related phases. This can be explained by the atomic radius and heat of mixing of the constituent elements. The phases precipitated at the initial stages of crystallisation indicate the possible presence of Frank–Kasper polyhedral structure in the amorphous alloys. Structural analysis reveals that the Laves and the anti-Laves phases have the same polyhedral structural unit, which is similar to the structural characteristics of glass.     

Improvement in the electrochemical properties of ZrMn2 hydrides by substitution of elements

The hydrogen-storage properties and the electrochemical properties are investigated for the alloys ZrMn₂Ni_x, ZrMnNi_1+x, Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_1−xFe_x and Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_0.85M_0.15. The C14 Laves phase forms in all the alloys ZrMn₂Ni_x (x=0.0, 0.3, 0.6, 0.9 and 1.2). Among the alloys ZrMn₂Ni_x, ZrMn₂Ni_0.6 has the largest discharge capacity (29 mAh/g) and a relatively good cycling performance, and shows a relatively easy activation. The C14 Laves phase also forms in all the alloys ZrMnNi_1+x (x=0.0, 0.1, 0.2, 0.3 and 0.4). Among the alloys ZrMnNi_1+x, ZrMnNi_1.0 has the largest discharge capacity (42 mAh/g) and a relatively good cycling performance, and shows the easiest activation. Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_1−xFe_x (x=0.00, 0.15, 0.30, 0.45 and 0.60) has the C14 Laves phase hexagonal structure. Their hydrogen storage capacities do not show significant differences. The discharge capacity just after activation decreases with an increase in the amount of the substituted Fe but the cycling performance is improved. The discharge capacity after activation of the alloy with x=0.00 is about 240 mAh/g at the current density 60 mA/g. Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_0.85Fe_0.15 is the best composition with a relatively large discharge capacity and a good cycling performance. The increase in the discharge capacity of Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_0.85Fe_0.15 with the increase in the current density (from 60 mA/g to 125 mA/g) is considered to result from the self-discharge property of the electrode. Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_0.85M_0.15 (M=Fe, Co, Cu, Mo and Al) alloys also have the C14 Laves phase hexagonal structure. The alloys with M=Co and Fe have relatively larger hydrogen storage capacities. The discharge capacities just after activation are relatively large in the case of the alloys with M=Co and Fe. The Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_0.85Co_0.15 alloy is best with a relatively large discharge capacity (257 mAh/g at the current density 250 mA/g for the 12^th cycle) and a good cycling performance. During activation form Ni-rich and Fe-rich regions on the surface of the Zr_0.5Ti_0.5Mn_0.4V_0.6 Ni_0.85Fe_0.15 alloy. They may act as the active sites for the electrochemical reaction. With the increase in the number of charge-discharge cycles for the Zr_0.5Ti_0.5Mn_0.4V_0.6Ni_0.85Fe_0.15 alloy, the quantities of the Zr and Fe dissolved in the electrolyte solution increase. This article is based on a presentation made in “The 2nd KIM-JIM Joint Symposium: Hydrogen Absorbing Materials”, held at Hanyang University, Seoul, Korea, October 27–28, 2000 under the auspices of The Korean Institute of Metals and Materials and The Japan Institute of Metals.     

Powder metallurgical processing of Ni–Ti–Zr alloys undergoing martensitic transformation: part I

Ni–Ti–Zr materials with Zr 12–25 at.% and Ni 42–50 at.% have been produced by powder metallurgy. Suitable temperatures for sintering in Ar-atmosphere Ni–Ti–Zr compacts are within the range 900–1000 °C. Sintering at temperatures above 1000 °C causes melting of the compacts with high Zr content. The presence of ZrC, ZrO₂, Zr₃O, TiO₂ and TiO of different modifications, complex oxides such as Ni₅TiO₇, Ti_0.5Zr_0.5O_0.2 and equilibrium phases after sintering at temperatures above 1000 °C in alloys with low Zr-content was derived from X-ray diffractometry. During sintering at temperatures below 1000 °C the phases belonging to the binary Ti–Ni and Ti–Zr systems were formed. Long-term sintering and slow furnace cooling allowed the precipitation of Ni₄Ti₃ and Ni₂Ti. The process of sintering is controlled by the diffusion of Ni in Ti and Zr particles during the early stages of sintering. Slow diffusion of Zr atoms in Ti₂Ni, Ti–Ni and diffusion of Ti atoms in Zr₂Ni, Ni–Zr controls the later stages of sintering.     

Embrittlement of Pd-coated Ni−Nb−Ti−Zr amorphous alloys during hydrogen permeation

In this study, we report results of an investigation into the failure of Ni₆₀Nb₁₅Ti₁₅Zr₁₀ amorphous alloys occurring during hydrogen permeation performed at 473 K and 573 K. However, the amorphous membrane did not fail during test performed at higher temperatures (673 K and 773 K). The failure of the Pd-coated Ni₆₀Nb₁₅Ti₁₅Zr₁₀ amorphous ribbon is attributed to the cracking of the hydrogenated Pd coating induced by the formation of α′ hydride phase in the low temperature range. 0     

Unusual devitrification behaviour in rapidly solidified Ti45Zr38Ni17 alloy

In this study, Ti₄₅Zr₃₈Ni₁₇ ribbons have been elaborated using planar flow casting method (v_quenching = 10⁶ K s⁻¹). The rapidly quenched samples, displaying a dispersion of nanoscaled β phase particles in an amorphous matrix, have been extensively characterised using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Devitrification behaviour, investigated by four-probe resistivity measurements and differential scanning calorimetry as well as high resolution TEM analysis, revealed the formation of nanometric quasicrystals (QC) during the first exothermic phase transformation as well as the precipitation of omega domains inside β particles. On the basis of these data, it has been noticed that nanoscaled β metastable particles had adopted the same temperature dependence as β metastable bulk. Furthermore, particular orientation relationships have been observed for QCs in the vicinity of β particles which have suggested probable influence of crystalline structure on the QCs growth, although the presence of such peculiar materials after annealing treatment could be mainly explained by an icosahedral short-range order prevailing in Ti–Zr–Ni melt and favouring their nucleation.     

Hydrogen permeation properties of Pd-coated Ni−Nb−Ti−Zr amorphous alloys

Hydrogen permeability of Pd-coated Ni₆₀Nb₁₅Ti₁₅Zr₁₀ and Ni₆₀Nb₂₀Ti₁₅Zr₅ amorphous alloys was measured in the temperature range of 673 K to 773 K and was compared with the results obtained using Ni₆₀Nb₄₀, a binary amorphous alloy. The permeability thus measured was found to increase moderately increasing temperature. A long-term permeation test for the Pd-coated Ni₆₀Nb₁₅Ti₁₅Zr₁₀ amorphous alloy revealed high permeation stability up to 16.6 h.     

Hydrogen solubility and diffusion studies of Zr-based AB2 alloys and sol–gel encapsulated AB2 alloy particles

Hydrogen solubility and hydrogen diffusion coefficients have been studied in Ti_0.1Zr_0.9(Mn_0.9V_0.1)_1.1Fe_0.5Ni_0.5, Ti_0.1Zr_0.9Mn_0.9V_0.1Fe_0.55Ni_0.55 and (Ti_0.1Zr_0.9)_1.1Mn_0.9V_0.1Fe_0.5Co_0.5 in the temperature range 450–650 °C with hydrogen gas pressure up to 100 mbar and hydrogen concentration up to 0.03 hydrogen atoms per formula unit. H₂ absorption is exothermic, and the values of partial enthalpy of solution per H atom are in the range from −370 ± 10 meV to −466 ± 50 meV. The silica embedded AB₂ alloy particles have been prepared by sol–gel technique. P–C isotherms of encapsulated AB₂ alloy particles have been obtained in the pressure and temperature ranges 0–30 bar and 30–100 °C, respectively. Diffusion of H interstitials in sol–gel encapsulated Ti_0.1Zr_0.9Mn_0.9V_0.1Fe_0.5Ni_0.5, (Ti_0.1Zr_0.9)_1.1Mn_0.9V_0.1Fe_0.5Ni_0.5 and (Ti_0.1Zr_0.9)_1.1Mn_0.9V_0.1Fe_0.5Co_0.5 alloy particles have been studied between 500 and 650 °C with H₂ gas pressure up to 100 mbar and H concentration up to 0.014 H atoms per formula unit. Diffusion coefficient (D) of H interstitials has been determined for all these samples from the kinetics of hydrogen absorption. The activation energies have been calculated from temperature dependence of diffusion coefficient and the values are in the range 416 ± 15–897 ± 50 meV.     

Improved mechanical behavior of Cu–Ti-based bulk metallic glass by in situ formation of nanoscale precipitates

The mechanical properties of Cu₄₇Ti₃₄Zr₁₁Ni₈, Cu₄₇Ti₃₃Zr₁₁Ni₈Fe₁, and Cu₄₇Ti₃₃Zr₁₁Ni₈Si₁ bulk metallic glasses prepared by copper mold casting are investigated. Room temperature compression tests reveal fracture strengths above 2000 MPa, Young’s moduli around 100 GPa and elastic strains slightly exceeding 2.0%. Only Cu₄₇Ti₃₃Zr₁₁Ni₈Si₁ exhibits distinct plastic strain due to a unique composite microstructure with in situ formed nanoscale precipitates in the glassy matrix.     

Peculiarities of ball-milling induced crystalline–amorphous transformation in Cu–Zr–Al–Ni–Ti alloys

An amorphization process in (Cu₄₉Zr_45−xAl_6+x)_100−y−zNi_yTi_z (x = 1, y, z = 0; 5; 10) induced by ball-milling is reported in the present work. The aim was investigation of the effect of Ni and Ti addition to Cu₄₉Zr₄₅Al₆ and Cu₄₉Zr₄₄Al₇ based alloys as well as type of initial phases on the amorphization processes. Also the milling time sufficient for obtaining fully amorphous state was determined. The entire milling process lasted 25 h. Drastic structural changes were observed in each alloy after first 5 h of milling. In most cases, after 15 h of milling the powders had fully amorphous structure according to XRD except for those ones, where TEM revealed a few nanosized crystalline particles in the amorphous matrix. In (Cu₄₉Zr₄₅Al₆)₈₀Ni₁₀Ti₁₀ alloy the amorphization process took place after 12 h of milling and the amorphous state was stable up to 25 h of milling. In the case of (Cu₄₉Zr₄₄Al₇)₈₀Ni₁₀Ti₁₀ alloy the powders have fully amorphous structure between 12 h and 15 h of milling.     

Effect of Co on the degradation of the hydrogen permeability of Ni-Nb-Zr amorphous membranes

The variation of the hydrogen permeability with time was monitored during the permeation of hydrogen through metallic amorphous membranes of Ni_45?XNb₃₀Zr₂₅Co_X (X=0, 7.5, and 15 at%) in the temperature range of 350 to 450 °C. For tests performed between 3 and 5 bars, the alloy with the medium content of Co, i.e., 7.5 at%, had the most pronounced degradation while the alloy without Co showed less of a decrease in the hydrogen permeability with time. The change in the hydrogen permeability with the Co content was discussed in connection with the difference in the activation barrier energy for crystallization in the alloys.     

Investigations of mechanically alloyed Ni–Zr–Ti–Si amorphous alloys with significant supercooled regions

This study examined the amorphization behavior of Ni₅₇Zr₂₀Ti_23−xSi_x (x=0, 1, 3) alloy powders synthesized by mechanical alloying technique. According to the results, after 5 h of milling, the mechanically alloyed powders were amorphous at compositions of Ni₅₇Zr₂₀Ti_23−xSi_x (x=0, 1, 3). The amorphization behavior of Ni₅₇Zr₂₀Ti₂₀Si₃ was examined in details. The conventional X-ray diffraction and synchrotron EXAFS results confirm that the fully amorphous powders formed after 5 h of milling. The thermal stability of the Ni₅₇Zr₂₀Ti_23−xSi_x amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the amorphous powders were found to exhibit a large supercooled liquid region before crystallization. The supercooled liquid regions, defined by the difference between T_g and T_x, (i.e. ΔT=T_g−T_x), are 95 K, 66 K, and 88 K, for Ni₅₇Zr₂₀Ti₂₃, Ni₅₇Zr₂₀Ti₂₂Si₁, and Ni₅₇Zr₂₀Ti₂₀Si₃, respectively.     

Containerless processing of the undercooled metallic melts — overview

Brief overview of current containerless electrostatic levitation processing technique and research progress of the area of bulk metallic glass formation is introduced. Undercooling behavior during solidification of the bulk metallic glass forming Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 alloy has been studied using the containerless electrostatic levitation processing technique. The melt is successfully undercooled to the glass transition temperature forming the amorphous phase with the proper thermal treatment. Differential scanning calorimetry (DSC) is used to determine the Gibbs free energy difference between the crystal and the undercooled liquid. The results indicate that the Gibbs free energy difference between the metastable undercooled liquid and the crystalline solid of the Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 alloy is relatively small compared to that of conventional metallic glass forming binary alloys even for large undercoolings. The hemispherical total emissivity of undercooled liquid is measured in the whole region of undercooled liquid state. Due to the combining effects of excellent thermal stability of the undercooled liquid in the Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 alloy with unique experimental technique of the containerless electrostatic levitation processing, it is possible to construct the complete time-temperature-transformation (TTT) diagram. The measured TTT diagram exhibiting the expected “C” shape can not be satisfactorily explained by the existing models due to the complex crystallization mechanisms.     

Characterization of interface between the particles in NiNbZrTiPt metallic glassy matrix composite containing SiC fabricated by spark plasma sintering

We investigated the microstructure, in particular, the interface structure between powder particles in the Ni_52.5Nb₁₀Zr₁₅Ti₁₅Pt_7.5 bulk glassy alloy composites containing 10 vol.%SiC particulates prepared by a spark plasma sintering (SPS) process by means of scanning and transmission electron microscopies. The SiC particulates were dispersed homogeneously in the Ni_52.5Nb₁₀Zr₁₅Ti₁₅Pt_7.5 glassy matrix. No crystallization of the Ni_52.5Nb₁₀Zr₁₅Ti₁₅Pt_7.5 glassy alloy took place during the SPS process. The good bonding states between SiC particulates and glassy matrix, as well as between glassy particles were recognized. No intermediate layer in the bonded interfaces was observed.