Boron Alloy Research Articles

The Active Dissolution of Iron‐Metalloid Metallic Glasses

The influence of metalloids on the dissolution of rapidly solidified iron‐metalloid materials has been examined. This paper presents results of a comparative study of the electrochemical behavior of pure polycrystalline iron and of rapidly quenched amorphous in both sulfate and chloride media. In acid sulfate solution, the single phase iron‐boron alloy behaved essentially as an iron electrode. The amorphous state per se was seen to exert little if any influence on the active dissolution kinetics. However, in chloride solutions the boron alloy exhibited characteristics differing from those of crystalline iron. Rapidly quenched and were also examined in sulfate media. These materials containing phosphorus display characteristics differing from iron and . and exhibited faster kinetics for the hydrogen reaction, and the anodic reaction was inhibited.

NeIGT 27 and 35

Abstract NeIGT 27 and 35 are high energy density, sintered permanent magnet iron, neodymium, boron alloys. They are ideal where space and weight reductions must be combined with high performance permanent materials. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on surface treatment. Filing Code: Fe-86. Producer or source: IG Technologies Inc..

Phase relations and hydrogen absorption of neodymium-iron-(boron) alloys

Based on an investigation of the phase correlations in the system Nd-Fe-B, a complete study of the hydrogen absorption of Nd-Fe-B alloys is presented, mainly concerning the permanent magnet material Nd2Fe14 B. Absorption isotherms of the compound Nd2Fe14 B and of the master alloy for permanent magnet production, Nd15Fe77B8, have been recorded and their hydrogenation behaviour is discussed. Thermal desorption spectra support the conclusion that neodymium hydride is the second hydride phase in the hydrogenated master alloy. In the Nd-Fe binary system, Nd2Fe17 was confirmed as the only equilibrium phase at 870 and 1170 K. The properties of a new ferromagnetic ternary hydride Nd2Fe17Hx,x = 0 to 5, with the Th2Zn17 type structure, space group\(R\bar 3m\), are reported.

Wear resistance of metastable Ni-B alloys produced by chemical vapor deposition

A manufacturing application of the chemical vapor deposition of nickel from Ni(CO) 4 is the near-net-shape production of high-quality mold or die forms. In certain high wear applications, e.g. transfer molding of a glass-filled epoxy, erosive wear of the nickel die can compromise dimensional control of the product. We have investigated the atmospheric pressure deposition (at 150–155°C) of Ni-B from Ni( CO) 4 + B 2 H 6 gas mixtures in order to develop alloys with improved hardness and wear resistance. The as-deposited alloys are metastable solid solutions of boron in nickel and contain up to 37 at.% B. Evaluations of the alloys in the as-deposited and annealed states have included micro-indentation hardness and 1000-cycle pin- on-disc wear and friction studies using glass-filled epoxy pins. Two high boron alloys are shown to provide excellent resistance to wear when sliding against the glass-filled epoxy.

Study of rapidly quenched Fe100−xMx crystalline alloys by Mössbauer effect spectroscopy (M=B, C, Al, Si, P)

The rapidly quenched, crystalline, Fe-rich Fe100−xMx system has been studied by 57Fe Mössbauer effect spectrometry. Boron and carbon alloys were found to have regions with cementite local structure. Small amounts of fcc γ-Fe were also observed in some of the cases. Furthermore, almost half of the carbon was concluded to be in interstitial solution. Upon annealing the carbon alloy, the fcc phase disappears to benefit formation of the cementite. In contrast, the alloys with aluminum, silicon, and phosphorous are substitutional solid solutions. After being annealed at 1073 K, they do not show changes in their hyperfine interactions nor in their crystalline structure. However, the lattice parameter of the alloy with phosphorous unexpectedly increased from a value below that corresponding to pure iron to another above it. These results are discussed on the basis of the metalloid solubilities in iron and their atomic sizes.

Development of a new method to produce melts suitable for the production of amorphous Fe−Si−B materials

Research work was performed on the development of a new reduction process for the melting and refining of boron containing alloys used in the production of amorphous material for transformer cores. Based on fundamental thermodynamics principles, a reduction refining process was developed which employs conventional steelmaking vessels for using steel scrap, ferro alloys, and boron ores to produce an Fe−Si−B alloy. The process can eliminate the need for ferro boron alloy, high purity iron, and remelt stock to produce the Fe−Si−B alloy. Process variables were established which show the effects of mixing time, reductant alloy additions, slag chemistry, and temperature on the reduction kinetics. Final melt chemistries have lower levels of sulfur, nitrogen, and other tramp elements than conventional methods for producing the Fe−Si−B melt.

A comparison between ion implantation and laser alloying of pure iron for oxidation resistance improvement

Following previous results concerning boron alloying by ion implantation or laser surface melting, we study the role of aluminium to improve the high temperature oxidation of iron. Laser alloying has a greater efficiency than ion implantation. The aluminium containing phases formed at the metal-scale interface are responsible for the observed protection. The behaviour of the laser surface alloy is quite comparable to that of conventional alloys Fe-5Al. These two techniques, ion implantation and laser irradiation, seem to be of importance for future developments of corrosion protection.

The Microstructure of Melt-Spun Iron Neodymium Permanent Magnet Materials

Rapidly-quenched iron rare-earth boron alloys, with appropriate heat treatment, exhibit commercially promising permanent magnetic properties. This paper will report the results of an AEM characterization undertaken to explain the origin of the magnetic properties of an iron-neodymium-boron alloy in terms of its microstructure. Ribbons of Fe76 Nd16 B8 were prepared by melt-spinning, and were subsequently annealed at 700°C for 6 minutes to promote growth of a fine-grained structure. Samples were prepared for AEM by ion-milling the ribbons on a cold stage and examined using a Philips 400T TEM/STEM equipped with an energy dispersive x-ray unit.Three different microstructures are commonly observed in these alloys, and several others have been found in isolated cases.

Mössbauer studies in rapidly quenched rare-earth iron boron alloys (abstract)

Rapidly quenched rare-earth (R)-iron boron alloys show large magnetic hysteresis when annealed around 700 °C. The hard magnetic properties of these alloys have been attributed to the presence of an anisotropic tetragonal phase with composition R2Fe14B. However, it is not yet clear when this phase is formed and how it affects the hard magnetic properties. Thermal analysis data, show a crystallization temperature around 400 °C which is much lower than the annealing temperature for the optimum properties. X-ray diffraction data do not show any significant changes after crystallization. In the present study we have used the Mössbauer effect to probe the products of crystallization and their changes during further annealing. Analysis of the 57Fe Mössbauer data has been performed considering a distribution of hyperfine magnetic fields. It is found that the average field changes from 250 kG for the amorphous alloy to 285 kG for the alloy annealed at 450 °C to 240 kG for the alloy annealed at 700 °C. The distribution is narrowed on increasing the annealing temperature and the Mössbauer spectra are indicative of phase segregation.

Hydrogen embrittlement of Ni 3Al+B

An experimental study is conducted to verify the hypothesis that Ni3Al, which exhibits an L1(2) structure and remains ordered up to the melting point, would be severely embrittled by hydrogen and that this effect would be reversible. Unlike its effect on Ni, boron alloying is found not to suppress hydrogen embrittlement in NiAl + B. A continuous oxide layer, however, is an effective barrier to the entry of hydrogen in this material. The reduction of accomodative slip processes, and the resultant buildup of stresses at the grain boundaries, appears to be the most likely cause of hydrogen embrittlement in NiAl + B and other ordered alloys. 11 references.

Standard molar enthalpy of formation of LaB6 by high-temperature calorimetry

Abstract The standard molar enthalpy of formation of LaB 6 has been determined calorimetrically for the first time by a new method based on reaction of the compound with solid platinum to form a liquid (platinum + lanthanum + boron) alloy. We found Δ f H m o (298.15 K) = −(400.4 ± 11.9) kJ mol −1 . The enthalpies of mixing Δ mix H m s-s of {(1 − x )Pt + x B}(1) alloys from Pt(cr) and B(cr) at compositions between x = 0.25 and x = 0.40 have been measured calorimetrically at (1377 ± 2) K. The most negative value of Δ mix H m s-s is about −4 kJ mol −1 found near x = 0.33.

Internal friction of palladium boron alloys

Internal friction of palladium boron alloys

Soviet superalloy ZHS6-K, effect of B/C modification

A Soviet nickel base cast superalloy, ZHS6-K, has been examined for its response to B/C modification. Three alloy chemistry variants, with 0.17C/0.02B, 0.06C/0.1 B and 0.03C/0.2B (wt%) have been investment cast and investigated for microstructure, heat-treatment, tensile properties, stress-rupture properties and hot corrosion resistance. The B/C modification of the alloy results in some improvement in the yield strength. However, the tensile ductility and the stress-rupture properties are considerably degraded. The nature of the hot corrosion is of a pitting type for the ZHS6-K, whereas it is of a broad front type for the high boron alloys.

Helium embrittlement of iron-chromium alloys

Abstract The helium embrittlement of Fe-(0–15)wt%Cr alloys was examined with high temperature tensile testing. Helium injection was performed by using cyclotron and partly by thermal neutron irradiation with boron alloying. The helium embrittlement was severer in lower chromium alloys. Helium bubbles were observed in Fe but not in Fe-15Cr, both of which contained 24 atppm helium tested at 1023K.

X-Ray and Neutron Diffraction Studies on Amorphous Transitionmetal—Boron Alloys (Fe-B,Co-B,Ni-B)

The atomic-scale structure of the amorphous metallic alloys Fe80B20, Co81·5B18·5, and Ni81·5B18·5 was investigated by X-ray- and neutron-diffraction covering a wide range of the ratio (fmetal/fboron) of the scattering factors of both components. The structure factors S (q) show a pronounced dependence on the ratio fmetal/fboron . In the cases of a small ratio an additional peak near q = 21.5 nm-1 appears in the structure factors from which a definite distance between B-B atoms, which are separated by metal atoms, is deduced. The corresponding structure factors show only weak oscillations in the range of the second and third maxima, which are followed by increased amplitudes at larger q's. By Fourier-transformation radial distribution curves were evaluated, from which the distances between the metal-metal-, the metal-boron-, and the boron-boron-atoms and the coordination numbers are extracted. From the splitted first maximum of the radial distribution function in the cases of small ratio fmetal/fboron also partial coordination numbers could be obtained. The results suggest some kind of short range order between the metal and the boron atoms.

Field-induced magnetic anisotropy of glassy iron-boron and iron-boron-silicon alloys near the eutectic composition

Measurements were made on a series of glassy iron–boron alloys to determine the association of the eutectic composition (lowest melting point) and the field-induced magnetic anisotropy. When the boron was increased from 15 to 22 at. %, the magnetic anisotropy was found to increase from 500 to 1300 J/m3. There was no sharp discontinuity in the vicinity of the eutectic. It appears that deviation from the eutectic does not greatly influence the value of the magnetic anisotropy, provided the samples are small and are drastically quenched. Specimens having the eutectic composition had the most reproducible values of anisotropy. The substitution of silicon for some of the boron in these alloys raises their Curie and crystallization temperatures. This makes possible a greater range of heat treating temperatures and permits better stress relief in the alloys. Also, the substitution of silicon permits better control of the magnetic anisotropy. This control may be a factor in obtaining improved magnetic properties since both low coercive force and low hysteresis loss in these materials depend upon obtaining the proper value of uniaxial anisotropy. Compositions that had values of the field-induced anisotropy of 1000 J/m3 had low values of core loss when properly heat treated.

Detection of boundary-layer transition with a laser beam

Fig. 5 burning time of particles as a function of the oven temperature. References 'Schadow, K., 'Study of Gaseous Nonequilibrium Effects in Particle-Laden, Ducted Flows for Improvement of the Combustion Efficiency, AIAA Paper 72-36 San Diego, Calif., 1972; Schadow, K., The Influence of Combustor Parameters on the Combustion of Particle-Laden Fuels in Ducted Flows, AIAA Paper 73-177, Washington, D.C., 1973. Boussios, A., Primarkammerprozesse fur Kombinationsantriebe, Kursus der Carl-Cranz-Gesellschaft uber Flugkorperantriebe in Braunschweig, March 19-23,197?. McLain, W.H., Identification of Exhaust Species from the combustion of LM and LMH Fuels, AFRPL TR-68-105, April 1968, Air Force Rocket Propulsion Lab., Edwards Air Force Base, Calif. Markowskii, L.Ya. and Kondrashev, Yu.D., The composition and Properties of Borides of the Elements of the first and second Groups of the periodic Systems, Zhurnal Neoranicheskoi Khimii, Vol. 11, No. 1, 1957, pp. 34-41. Secrist, Childs, US Atomic Energy Rept. TID-17149, 1962. Hsia, H., Air-Augmented Combustion of Boron and BoronMetal Alloys, Final Rept. AFR DL-TR-71-80, June 1971, Air Force Research Lab., Wright-Patterson Air Force Base, Ohio.

The oxidation of the hypophosphite ion by water, catalysed by metal–phosphorus and metal–boron alloys

The hydrolysis of the hypophosphite ion occurs according to equation (i) and is catalysed by nickel–phosphorus, H2PO2–+ H2O [graphic omitted] → H2PO3–+ H2(i) cobalt–phosphorus, and nickel–boron alloys. The stoicheiometry and the kinetic behaviour have been examined by measuring the hydrogen evolved in the catalysed hydrolysis at 98·7 °C. Further information concerning the reaction mechanism has been obtained by carrying out the reaction in D2O or D2O–H2O mixtures. The reaction can be followed by 1H n.m.r. measurements of the concentrations of the species H2PO2– and H2PO3–. The deuterium content of the gas evolved has also been studied. A reaction mechanism is proposed involving simultaneous reactions in which the hypophosphite molecule exchanges either one or both phosphorus-bound hydrogen atoms with the solvent.

Hydrolysis of the borohydride ion catalysed by metal–boron alloys

The hydrolysis of the borohydride ion according to the equation (i) is catalysed by nickel–boron and cobalt–boron, BH4–+ 3H2O → H2BO3–+ 4H2(i) alloys. The metal-catalysed hydrolysis has been studied at 22·0 °C by measurement of the hydrogen gas evolved. Analysis of the gas evolved when the reaction is carried out in deuterium oxide shows that approximately half the hydrogen evolved originates from the borohydride and half from the solvent. The deuterium content of the gas increases with reaction time. In mixtures of H2O and D2O, preferential hydrogen evolution occurs and isotope separation factors of 8·5 (for a nickel–boron catalyst) and 9·2 (for a cobalt–boron catalyst) have been derived.

A study of neutron irradiation damage in copper and a dilute copper-boron alloy

Abstract Transmission electron microscopy has been used to examine irradiation-induced damage in pure copper and in a solid solution copper-0.001 w/o boron alloy after simultaneous neutron irradiation to an integrated fast neutron dose of 1.1 × 1020 cm−2 at ∼ 60°c. The results demonstrate that the resolvable damage differs considerably in these materials, both in its initial distribution and in its post-irradiation annealing behaviour these differences are considered to be a consequence of the transmutation of the boron-10 atoms in the alloy. After post-irradiation annealing, the damage in both materials clearly consists of two components; coarsely distributed dislocation segments and loops and a finer distribution of small clusters. The annealing behaviour of both components has been examined closely after annealing between 350°c and 650°c, the temperature range in which the principal changes occurred, and the morphology and nature of the loops comprising the coarser component have been determined. Consideration is given to the mechanisms involved in the annealing of the damage, particular emphasis being placed on accounting for the significant influence exerted by the boron, helium and lithium atoms. Spherical precipitates, believed to result from aggregation of lithium atoms, have been observed in the alloy after annealing between 450°c and 650°c. However, helium bubbles could not be detected and the possible reasons for this are discussed.