Showing papers on "Alloy published in 1978"
TL;DR: In this paper, surface films formed by adsorption of benzotriazole (BTA), on copper and copper alloys have been studied by X-ray photo-electron spectroscopy (XPS).
254 citations
TL;DR: In this article, the composition and structure of passive films formed on a series of iron-chromium alloys in de-aerated 1M H 2 SO 4 were quantitatively studied.
235 citations
TL;DR: The feasibility of fabricating fiber-reinforced aluminum alloys by addition of discontinuous fibers to vigorously agitated, partially solid metal slurries was investigated in the first phase of the program as mentioned in this paper.
Abstract: The feasibility of fabricating fiber-reinforced aluminum alloys by addition of discontinuous fibers to vigorously agitated, partially solid metal slurries was investigated. In the first phase of the program, reported herein, emphasis was placed on the study of interface interactions between polycrystalline A12O3 fibers and Al-2 to 8 pct Mg, Al-4.5 pct Cu and Al-4.5 pct Cu-1 to 2 pct Mg alloys. In general, it was observed that the incorporation of fibers could be readily achieved by this technique, and that fibers appeared wetted after a few minutes of contact with the melt. The composites produced exhibited an intimate, void free bond between the constituents. In addition, a region of significantly altered microstructure resulted from accumulation of oxide and/or aluminate particles which either formed within the melt and were attached to the moving fibers, or used the fiber surface as a substrate to grow on. Microscopic examination of this interaction zone and thermodynamic considerations indicate that it consists of fine α-Al2O3, aluminates, oxides of the alloying elements, and probably some intermetallic compounds. For example, it is shown that a stable MgAl2O4 spinel forms at the interface of A12O3 fibers and Al-Mg alloys. Examination of composite specimens fractured under tension indicated that the interfaces produced were strong enough to permit the transfer of loads at strengths in the order of 250 to 350 MPa.
232 citations
TL;DR: The effect of small amounts of yttrium and hafnium (up to 1.5 wt.%) on the oxidation behavior of Co-Cr-Al alloys in the temperature range 1000-1200°C for times up to 1000 hr in air has been studied as mentioned in this paper.
Abstract: The effect of small amounts of yttrium (up to 1 wt. %) and hafnium (up to 1.5 wt.%) on the oxidation behavior of Co-Cr-Al alloys in the temperature range 1000–1200°C for times up to 1000 hr in air has been studied. The major portion of the study has been concerned with Co-10Cr-11Al base alloys. Both isothermal and cyclic tests have been carried out; the cycle used consisted of 20 hr at temperature, followed by cooling to room temperature. Both additions reduce the overall oxidation, Hf somewhat more so than Y. In part, this is due to the improved adhesion between scale and alloy reducing scale spallation at temperature, and in part due to possible modification of the Al2O3 grain size. The former factor is far more critical under thermal cycling conditions. Under isothermal conditions the oxidation rate increases with increasing Hf content with all but the 1.5 wt.% alloy oxidizing more slowly than the Hf-free alloy; increase in Y content has the reverse effect. Under thermal cycling conditions the 0.3 and 1.0 wt.% Hf alloys show the lowest overall weight gain. Metallographic evidence suggests that the improved scale adhesion is due principally to a pegging mechanism; the active elements promote the growth of intrusions of Al2O3 into the alloy. However, if the intrusions are too large, they can act as initiators of scale failure.
212 citations
TL;DR: In this paper, the relative glass-forming ability of metallic alloys is considered in terms of a parameter ΔT ∗ = (T liq mix − T liq )/T lq mix, which represents the departure of the alloy liquids temperature from that of the simple rule of mixtures liquids temperature, Tliqmix, and a rapid assessment of the GFA of novel compositions may in general be obtained simply from a knowledge of the melting points of the pure components and the liquidust emperatures of the alloys.
Abstract: The relative glass-forming ability (GFA) of metallic alloys is considered in terms of a parameter ΔT ∗ = (T liq mix − T liq )/T liq mix , which represents the departure of the alloy liquids temperature, Tliq, from that of the simple rule of mixtures liquids temperature, Tliqmix. For values of ΔT ∗ > 0.20 a metallic system is likely to form a glass by melt-quenching in useful thicknesses (i.e. > 20 μm) at a cooling rate of 105−107 K s−1. Hence, a rapid assessment of the GFA of novel compositions may in general be obtained simply from a knowledge of the melting points of the pure components and the liquidust emperatures of the alloys.
197 citations
TL;DR: In this article, a large fraction of the Pt becomes "inaccessible" to hydrogen chemisorption upon treatment in hydrogen at high temperature (> 500 °C) and the results agree with the assumption that the highly dispersed particles form an alloy with the Al from the support.
173 citations
PARC1
TL;DR: In this paper, the Raman spectra have been obtained from thin films of silicon-hydrogen and siliconhydrogen-deuterium alloys deposited from low pressure, r.f. excited plasmas in mixtures of SiH4/Ar and SiH 4/D2/Ar respectively.
Abstract: Infra-red and Raman spectra have been obtained from thin films of silicon-hydrogen and silicon-hydrogen-deuterium alloys deposited from low pressure, r.f. excited plasmas in mixtures of SiH4/Ar and SiH4/D2/Ar respectively. The spectra are analysed using a valence-force-field model based on effective force constants determined from SiH4. For alloys deposited onto substrates held at 25°C it is concluded that the structure is best described as a pseudobinary alloy of the form (Si)x(Si2H4)1_ x . In contrast, for material deposited on to a substrate at a temperature T s⩾250°C, the hydrogen is incorporated onto Si-sites containing predominantlv one H-atom.
167 citations
TL;DR: In this article, the authors determined the kinetic parametes for the oxygen evolution reaction on 50-50 atom percent alloys of Ru, Ir, RuO 2, IrO 2 and IrPt and compared with results obtained using ruthenium, iridium, platinum, and RuO2 /TiO 2 electrodes.
163 citations
TL;DR: The morphology and chemical analysis of the complex phases present in cast nickel aluminium bronze, of nominal composition 10% aluminium, 5% nickel and 5% iron, have been investigated using optical and electron microscopy techniques and energy dispersive analysis as mentioned in this paper.
Abstract: The morphology and chemical analysis of the complex phases present in cast nickel aluminium bronze, of nominal composition 10% aluminium, 5% nickel and 5% iron, have been investigated using optical and electron microscopy techniques and energy dispersive analysis. It has been shown that α, β and four forms of κ can exist in the ascast microstructure of this alloy. Heat treatment can lead to the precipitation of a further κ phase which differs in morphology and chemical composition to those present in ascast structures.
160 citations
TL;DR: In this article, the effects of alloy purity and state of aging on the fracture mechanism and resultant toughness of pure Al-Cu alloys, and commercial duralumin were examined, and good agreement was obtained between experimental results of toughness and those predicted from a knowledge of the tensile properties.
Abstract: The object of the paper is to examine the effects of alloy purity and state of aging on the fracture mechanism and resultant toughness of pure Al-Cu alloys, and commercial duralumin. In pure alloys, the transition from a shear to an intergranular mode of fracture with overaging is associated with changes in the nature and size of the matrix precipitate, which affect the slip character. In the corresponding commercial purity alloys, no such fracture mode transition occurs. The presence of second-phase dispersoids inhibits planar slip, and in the overaged state inclusion-matrix interfaces present a suitable alternative site to the grain boundaries for strain accumulation, resulting in debonding leading to the initiation of voids, which subsequently grow and coalesce. The fracture toughness, as conventionally measured, indicates the material’s resistance to crack initiation rather than propagation and is effectively independent of fracture mode. The work hardening capacity has a marked effect on void size, and is shown to be a sensitive indicator of fracture toughness in both pure and commercial alloys. Based on a simple model, good agreement is obtained between experimental results of toughness and those predicted from a knowledge of the tensile properties.
160 citations
TL;DR: In this article, the interdiffusion coefficients in Al-Si alloys were determined by Matano's method in the tem-perature range from 753 to 893 K with the couple consisting of pure aluminum and an Al- Si alloy.
Abstract: Interdiffusion coefficients in Al-Si alloys were determined by Matano’s method in the tem-perature range from 753 to 893 K with the couple consisting of pure aluminum and an Al-Si alloy. Temperature dependence of the impurity diffusion coefficients of Si in Al, obtained by extrapolation of the concentration dependence of the interdiffusion coeffi-cient to zero mole fraction of Si, is given by the following equation: DSi/Al = (2.02+0.97
-0.66 × 10-4 exp [-(136 ±3) kJ mol-1/RT] m2/s. p ] The Kirkendall marker was found to move toward the Si-rich side, indicating that the Si atom diffuses faster than the Al atom in Al-Si alloys. From the interdiffusion coeffi-cient and the marker shift, the intrinsic diffusion coefficients were calculated. The difference in the activation energies (ΔQ) between the impurity diffusion of Si in Al and the self-diffusion of Al was estimated by means of the asymptotic oscillating po-tential and the Le Claire theory. The calculated value of ΔQ is in fair agreement with the experimental value. The vacancy-solute binding energy for Si in Al was also dis-cussed based on the diffusion data.
TL;DR: In this paper, four aspects of the sputtering phenomenon are considered with reference to binary targets and the actual responses of a rather large number of binary oxide and alloy targets are most simply summarized by noting the following: (a) CdO preferentially loses.
TL;DR: In this article, the available data and information on the thermal conductivity of ten selected binary alloy systems and the recommended values resulting from critical evaluation, analysis, and synthesis of available data are discussed.
Abstract: This work reviews and discuss the available data and information on the thermal conductivity of ten selected binary alloy systems and presents the recommended values resulting from critical evaluation, analysis, and synthesis of the available data. The ten binary alloy systems selected are the systems of aluminum‐copper, aluminum‐magnesium, copper‐gold, copper‐nickel, copper‐palladium; copper‐zinc, gold‐palladium, gold‐silver, iron‐nickel, and silver‐palladium. The recommended values given include values of the total thermal conductivity, electronic thermal conductivity, and lattice thermal conductivity. The uncertainty of the values is generally of the order of ±10%. The values for each of the alloy systems except two are given for 25 alloy compositions: 0.5, 1, 3, 5, 10(5)95,97,99, and 99.5%. For most of the alloy compositions, the values cover the temperature range from 4 K to the solidus temperature or 1200 K. In addition, reliable methods for the estimation of the electronic and lattice thermal conductivities of alloys have been developed in this study.
Patent•
18 Dec 1978
TL;DR: Nickel base superalloy single crystal articles formed from an alloy family and heat treated are described as is the process employed as discussed by the authors, and the articles are substantially free from cobalt and the grain boundary strengtheners such as carbon, boron and zirconium.
Abstract: Nickel base superalloy single crystal articles formed from an alloy family and heat treated are described as is the process employed. The articles are substantially free from cobalt and the grain boundary strengtheners such as carbon, boron, and zirconium. The heat treatment process homogenizes the microstructure, and refines the gamma prime morphology.
Book•
01 Sep 1978
TL;DR: In this paper, the authors present an approach for the separation of metal components based on the properties of the metal components and their properties, such as properties of fracture in a Ductile Material, fracture in Brittle Material, deformation in a Brittle material, and reduction of brittle fracture.
Abstract: 1 Introductory Materials Concepts Chp 1.Structure and Properties 1-1 Atomic Packing 1-2 Crystal Structure 1-3 Grain Structure 1-4 Mechanical Properties and Testing 1-5 Physical Properties Chp 2.Deterioration of Material Properties 2-1 Fracture in a Ductile Material 2-2 Fracture in a Brittle Material 2-3 Suppression of Brittle Fracture 2-4 Linear Elastic Fracture Mechanics 2-5 Property Deterioration 2-6 Property Deterioration from Cyclic Loading 2 Strengthening Mechanisms Chp 3.Solid-Solution Strengthening 3-1 Formation of Solid Solutions 3-2 Mechanism of Solidification 3-3 Solidification of Pure Metals 3-4 Solidification of Metal Alloys 3-5 Diffusion 3-6 Segregation in Metal Alloys 3-7 Real Solid Solutions 3-8 General Properties of Solid Solutions Chp 4.Deformation Hardening and Annealing 4-1 Plasticity of Metals 4-2 Property Changes in Deformation Hardened Metals 4-3 Annealing 4-4 Property Changes in Annealed Metals Chp 5.Multiphase Stregthening 5-1 Binary Eutectics 5-2 Intermetallic Compounds 5-3 Multicomponent Eutectics 5-4 Microstructure of Multiphase Materials 5-5 Generalized Properties of Multiphase Materials Chp 6.Precipitation Hardening 6-1 General Mechanism of Precipitation Hardening 6-2 Precipitation from Solid Solution 6-3 Stages of Precipitation Hardening 6-4 Variables Affecting Precipitation Hardening 6-5 Prcippitation Hardening of Cu-Be Alloys Chp 7.Martensitic Transformation 7-1 The Fe-Fe3C Phase Diagram 7-2 Alloys of Iron and Carbon 7-3 Microstructure of Nonhardened Steel 7-4 Heat Treatment of Eutectoid Steel 7-5 The Martensite Transformation 7-6 Heat Treatment of Noneutectoid Steel 7-7 Physical Property Changes during Martensite Formation 7-8 Tempering of Martensite 7-9 Microstruture of Isothermally Transformed Steel 7-10 Generalized Properties of Heat-Treated Steel 3 Metallic Materials Engineering Chp 8.Low-Carbon Steels 8-1 Terms Related to Steelmaking Processes 8-2 Grain Size of Steel 8-3 Nonhardenable Low-Carbon Steels 8-4 High-Strength Low-Carbon Steel Chp 9. Medium Carbon Steels 9-1 Classification of Medium Carbon Steels 9-2 Hardening Carbon Steels 9-3 Hardening Alloy Steels 9-4 Ultra High-Strength Steels Chp 10.High Carbon Steels 10-1 Classification of High-Carbon Steels 10-2 Heat Treatment of High-Carbon Steels 10-3 Cemented Carbides Chp 11.Stainless Steels 11-1 Phase Diagrams of Stainless Steels 11-2 Stainless Steel Alloy Designations 11-3 Heat Treatment of High-Carbon Steels 11-4 Mechanical Properties of Stainless Steels 11-5 Corrosion Resistance of Stainless Steels Chp 12.Cast Irons 12-1 Cast Iron (Fe-C-Si)Phase Diagram 12-2 Gray Cast Iron Solidification 12-3 Ductile Cast Iron Solidification 12-4 Concepts of Graphitization in Cast Iron 12-5 Properties of Cast Iron Chp 13.Aluminum Alloys 13-1 Work Hardenable Wrought Aluminnum Alloys 13-2 Heat Treatable Aluminum Alloys 13-3 Cast Aluminum Alloys 13-4 Residual Stresses in Aluminum Alloys 13-5 Alumminum-Lithium Alloys Chp 14.Copper and Copper Alloys 14-1 Copper Alloy Designations 14-2 Unalloyed Coppers 14-3 Brasses:Cu-Zn Alloys 14-4 Tin Bronzes: Cu-Sn Alloys 14-5 Silicon and Aluminum Bronzes 14-6 Cast Copper-Based Alloys Chp 15.Magnesium Alloys 15-1 Magnesium Alloy Designations 15-2 The Nature of Magnesium Alloying 15-3 Cast Magnesium Alloys 15-4 Properties of Magnesium Alloys Chp 16.Titanium Alloys 16-1 Unalloyed Titanium 16-2 Phase Diagrams of Titanium Alloys 16-3 Heat Treatment of Titanium Alloys 16-4 Properties of Titanium Alloys 16-5 Applications of Titanium Alloys Chp 17.Metals for High-Temperature Service 17-1 High-Temperature Performance of Refractory Metals 17-2 Nickel and Iron Based Superalloys 17-3 Cobalt Based Superalloys 17-4 Vanadium, Niobium, and Tantalum 17-5 Chromium, Molybdenum,and Tungsten 17-6 Refractory Metal Coatings 4 Nonmetallic Materials and Composites Engineering Chp 18.Engineering Polymers 18-1 Bonding and Structure in Polymers 18-2 Generalized Properties of Polymers 18-3 Olefin, Vinyl, and Related Polymers 18-4 Thermoplastic Polymers 18-5 Thermosetting Polymers 18-6 Elastomeric Polymers Chp 19.Ceramics and Glasses 19-1 A Ceramic Phase Diagram (A12O3-SIO2) 19-2 Traditional Ceramics: Clay, Refractories, and Abrasives 19-3 Structure and Properties of Engineering Ceramics 19-4 Characteristics Of Glass Chp 20.Composite Materials 20-1 Forms and Properties of Composite Reinforcing Materials 20-2 Forms and Properties of Composite Matrix Materials 20-3 Metal Matrix Composites 20-4 Polymer Matrix Composites 20-5 Ceramic Matrix Composites 20-6 Carbon and Graphite Composites
TL;DR: In this article, the authors investigated the kinetics of surface processes involved in the growth of certain III-III-V alloy films from beams of their constituent elements using modulated beam techniques.
TL;DR: In this paper, it was shown that AI-Cu-Mg-Ag alloys have a high response to hardening in the artificially aged condition and this effect is considered to arise because silver changes the ageing process occurring in the equivalent ternary Al-CuMg alloy and promotes precipitation of thin plates of a monoclinic form of the phase θ(CuAl2) on the matrix planes.
Abstract: Castings made from AI-Cu-Mg-Ag alloys have a high response to hardening in the artificially aged condition This effect is considered to arise because silver changes the ageing process occurring in the equivalent ternary Al-Cu-Mg alloy and promotes precipitation of thin plates of a monoclinic form of the phase θ(CuAl2) on the {111} matrix planes Replacing silver with cadmium also causes increased hardening, although the effect is less and arises from a refinement in the size of precipitates formed in the existing ageing process
TL;DR: In this article, the results obtained show that this method was capable of giving reproducible undercooling results which in most cases were much larger than had been achieved by the use of other techniques.
TL;DR: In this paper, anodic polarization curves of amorphous and crystalline Cu 50 Ti 50 and Cu 50 Zr 50 alloys have been examined in various acidic, neutral and alkaline solutions.
Abstract: Corrosion rates and anodic polarization curves of amorphous and crystallinecu 50 Ti 50 and Cu 50 Zr 50 alloys have been examined in various acidic, neutral and alkaline solutions. The amorphous alloys are very stable in acidic and alkaline solutions, but unstable in agressive chloride solutions. The corrosion resistance of these amorphous alloys is higher than that of the crystallized alloys. The high corrosion resistance of amorphous alloys is attributable to the high chemical homogeneity of amorphous alloys without localized crystalline defects such as precipitates, segregates, grain boundaries, etc. Metalloid elements play an important role in the corrosion behavior of amorphous alloys; the addition of phosphorus to amorphous CuTi alloy greatly increases the corrosion resistance, even in 1N HCl.
TL;DR: In this paper, the effect of applied stress on the γ→α martensitic transformation in spherical iron precipitates under the uniaxial applied stress was examined by using a Cu-1 wt.% Fe alloy single crystal.
TL;DR: The theory and practice of rare earth additions to steel are reviewed in this article, where it is predicted that rare earth elements have a very strong affinity for oxygen and sulphur and are capable of reducing the oxygen and sulfur contents of steel as well as modifying the inclusions remaining after solidification.
Abstract: The theory and practice of rare earth additions to steel are reviewed. On the basis of thermodynamic data it is predicted that rare earth elements have a very strong affinity for oxygen and sulphur and are capable of reducing the oxygen and sulphur contents of steel as well as modifying the inclusions remaining after solidification. The formation of rare earth-lead compounds which should offset the detrimental effects of lead is also predicted. Laboratory and plant experience of rare earth treatment of steel shows the thermodynamic predictions to be true. The different methods of adding rare earth metals to steel are summarized and it is shown that recoveries can be improved by using plunging and encapsulation techniques instead of simply adding the alloy to the metal stream during tapping or teeming. The efficiency of rare earth treatment is also enhanced by the use of stable refractor iessuch as magnesia. The composition, constitution, and methods of identification of rare earth oxides, sulphide...
TL;DR: In this paper, the microstructures of permanent magnet alloys after isothermal aging, thermomagnetic treatment, and step aging have been characterized by transmission electron microscopy and by measurement of the Curie temperature.
Abstract: The microstructures of an Fe-31wt%Cr-23wt%Co ductile permanent magnet alloy after isothermal aging, thermomagnetic treatment, and step aging have been characterized by transmission electron microscopy and by measurement of the Curie temperature. Isothermal aging itself produces the undesirable microstructure. Aging at 600°C develops the magnetic chromium-rich phase. Aging at 600°C produces a nonmagnetic chromium-rich phase dispersed within the iron-rich phase. The effect of thermomagnetic treatment on the microstructure of the alloy is discussed in comparison with that of Alnico alloys. Step aging produces the deskable microstructure, viz., the elongated ferromagnetic phase imbedded in the paramagnetic phase.
TL;DR: The technique of microautoradiography at the electron microscope scale is used to describe the local repartition of hydrogen introduced by cathodic charging in an Fe-Ti alloy (0.15 Wt% Ti) as mentioned in this paper.
Abstract: The technique of microautoradiography at the electron microscope scale is used to describe the local repartition of hydrogen introduced by cathodic charging in an Fe-Ti alloy (0.15 Wt% Ti)...
TL;DR: In this article, a time-temperature transformation diagram has been constructed from X-ray diffraction examination of annealed samples of amorphous Fe-17 at %B alloy prepared by a splat-quenching technique.
Abstract: Amorphous Fe-17 at %B alloy prepared by a splat-quenching technique was annealed at temperatures ranging from 250 to 500° C for different periods. A time-temperature transformation diagram has been constructed from X-ray diffraction examination of annealed samples. On annealing the alloy at a pressure of 50 kbar, an appreciable retardation of crystallization was observed. The crystalline phase precipitated first from the amorphous matrix at 1 bar. This was α-Fe containing a small amount of boron, but at 50 kbar this was a mixture of α-Fe(B) and intermetallic phase Fe3B. Under the increased pressure of 100 kbar the mode of the crystallization was further changed and Fe3B became the first precipitating phase. Preferential formation of Fe3B under pressure can be explained assuming a modified dense-random packing model for the amorphous structure.
TL;DR: In this paper, an analytical solution to the diffusion equation is developed for the case when a phase change occurs in the alloy because of less noble metal depletion and an expression is also presented for the profile developed in the limiting case where depletion is determined by scale evaporation.
Abstract: The assumptions involved in Wagner's original treatment of alloy depletion profiles are examined and found to be acceptable for many situations. Finite difference analyses do not result in profiles which are significantly different from those obtained by the much simpler analytical solution once steady-state parabolic growth is established. Consequently an analytical solution is preferred and its combination with the classical Wagner expression for scale growth leads to a unified description of alloy oxidation when only the least noble metal is oxidized. The description is tested for an Fe-27.4wt.% Cr alloy oxidized at 1273°K and agreement between theoretical and experimental results is satisfactory. Alternative treatments of alloy oxidation which require that there be no recession of the alloy-scale interface are discussed and it is concluded that this assumption is unnecessarily restrictive in many cases. Suggestions that the oxidation of austenitic steels is controlled by diffusion in the alloy and that an interfacial transfer step is of importance in determining the oxidation rate in some cases are shown to be based on invalid assumptions. An analytical solution to the diffusion equation is developed for the case when a phase change occurs in the alloy because of less noble metal depletion and an expression is also presented for the profile developed in the limiting case where depletion is determined by scale evaporation.
TL;DR: In this article, the gas phase oxidation of Inconel 600 alloy has been studied under very mild oxidation conditions, and the film composition and structure were studied as a function of oxidation time, temperature, oxygen concentration and surface topography.
TL;DR: In this paper, a range of commercial aluminium/magnesium alloys were tested at temperatures from 20 to 300°C at a variety of strain rates, and tests were carried out in both uniaxial and baoxial tension.
TL;DR: In this paper, the hydrogen diffusion coefficient of the Pd-Y diffusion membrane has been shown to have a substantially greater hydrogen solubility gradient in this alloy membrane compared with that in Pd25% Ag.
Abstract: Reproducible permeability data have been obtained for the approximately isoelectronic alloys Pd-25 at.% Ag, Pd-5.75 at.% Ce and Pd-8 at.% Y; the previously observed enhanced performance of the Pd-Y alloy has been confirmed. Hydrogen solubility measurements have also been made for the three alloys over the same range of pressures and temperatures as those employed in the permeability studies. Using these data the detailed shapes of the permeability versus temperature plots have been successfully analysed and it has been shown that the hydrogen diffusion coefficients in all three alloys are very similar. The present results show clearly that the enhanced performance of the Pd-Y diffusion membrane is due to the substantially greater hydrogen solubility gradient in this alloy membrane compared with that in Pd-25% Ag.
TL;DR: Laser surface melting experiments have been carried out on the refractory-element-rich alloy M2 and the chromium-rich Alloy 440-C as mentioned in this paper, where the microstructure contains both δ-ferrite and austenite with residual amounts of carbides.
Patent•
20 Apr 1978
TL;DR: In this paper, a method for the manufacture of materials such as tools, machines or parts thereof composed of at least two sections joined together by composite sintering from sintered alloys with an iron, nickel or cobalt base is described.
Abstract: Described herein is a method for the manufacture of materials such as tools, machines or parts thereof composed of at least two sections joined together by composite sintering from sintered alloys with an iron, nickel or cobalt base wherein at least two powdered metallic mixtures having differing metal carbide contents are separately prepared and poured, one after the other, into a mold and then formed into a pressed body; the pressed body is then sintered at the lowest temperature sufficient to cause alloy formation in the mixture having the lowest sintering temperature, and then hot-pressed to complete alloy formation in the pressed body and achieve maximum density