Ultrahigh-Temperature HfB2-Based Ceramics: Structure, …

Hafnium diboride materials with high service temperatures were produced with additions of silicon carbide, molybdenum disilicide, and zirconium nitride [12, 18,19,20,21,22,23]. The ceramic composites oxidize at 1.5 mg/cm 2 ∙ h at 1500°C within 5 h . The bending strength at T = 1500°C was 465 MPa and, in some cases, 600 MPa .

Molybdenum Hafnium Carbide (MHC) Alloy | AMERICAN …

Molybdenum Hafnium Carbide (or Carbon) Alloy is a particle-reinforced molybdenum-based alloy containing hafnium carbide in the proportions of 0.8-1.4% hafnium and 0.05-0.15% carbon. MHC is a high strength alloy with high thermal conductivity and creep resistance, low thermal expansion, and a high recrystallization temperature. These …

A Comparative Study on Modified Johnson–Cook and …

Hafnium carbide (HfC), a compound with a NaCI structure and the highest melting temperature (3890 °C) among all carbides, is an ideal particle hardener for Mo, resulting in so-called molybdenum-hafnium-carbide alloy (Ref 3, 4).

On the chemistry of the carbides in a molybdenum base Mo …

The main focus of the present work is on the investigation of carbides present after sintering in the molybdenum base alloy MHC (Mo-Hf-C) which is produced via a powder route. The alloy has a nominal content of 0.65 at.% hafnium and 0.65 at.% …

Carbon

The creep behavior of arc-melted molybdenum-0.5% hafnium carbide and commercial purity molybdenum was evaluated at temperatures from 1600 to 2100 K while subjected to stresses of 10–60 MPa in a ...

Densification, strengthening and toughening in hafnium carbide …

Hafnium carbide (HfC) possesses low toughness and damage tolerance, which limits its application as high-temperature structural materials. Here we report a route to fabricate a dense HfC with high toughness by incorporating a two-component SiCN (silicon carbonitride) sintering aid, which is composed of SiCN and turbostratic carbon in …

Elmet-Starck Molybdenum Hafnium Carbide Powder, …

Elmet-Starck Molybdenum Hafnium Carbide Powder, Metallurgy Alloy Bar MHC. Description of Product: This specification covers molybdenum alloy (molybdenum + 1.2% hafnium) wrought bar produced from pressed and sintered metallurgy billet. Structure: The MHC alloy bars can be supplied in the recrystallized condition.

Properties of tungsten-rhenium and tungsten-rhenium with hafnium carbide

Historically, tungsten-25wt.% rhenium alloy has been manufactured into wire for the thermocouple market, but recent demands for high-temperature structural components have forced the development of novel processing techniques for tungsten-rhenium and tungsten-rhenium with hafnium carbide. With a melting temperature of …

Hardening of molybdenum by microadditions of hafn-ium and HfC carbide

Tensile Deformation of Molybdenum as a function of Temperature and Strain Rate. R. P. Carreker R. W. Guard. Materials Science. 1956. True stress-true strain data are given for nominally pure molybdenum (99.95 pet) over the temperature range −196° to 1540°C (0.027 to 0.63 T/TJ. Strain rate sensitivity was determined by rate change….

A reevaluation of the mechanical properties of molybdenum …

It is the purpose of this paper to réexamine data on the behavior of molybdenum- and tungsten-based alloys which are strengthened by hafnium carbide. This reanalysis suggests that claims of apparently unusual high-temperature behavior in the above systems, specifically (1) the "solute-weakening" effect of hafnium and (2) the fact that …

High‐Temperature Tensile Properties of a Molybdenum…

Tensile properties of a molybdenum‐5 at % rhenium‐0.5 at % hafnium carbide alloy were evaluated with a strain rate of 10 −3 /sec over a temperature region of 1200 to 2400 K in vacuum. The yield strength, tensile strength, solution induced and dispersion induced strength increments, strain‐hardening exponent, and tensile …

MHC1785 Molybdenum Hafnium Carbon Alloy (MHC Alloy)

Molybdenum hafnium carbide (MHC) alloy is a particle-reinforced molybdenum alloy that contains hafnium and carbon. Stanford Advanced Materials (SAM) can provide different shapes of Molybdenum Hafnium Carbon Alloy (MHC Alloy) with the custom proportion of Hf and Carbon. Standard forms include a bar, sheet, plate, disc, and special shapes are ...

Molybdenum-Hafnium-Carbon (MHC)

Molybdenum-hafnium carbide (MHC) is highly temperature-resistant, has a high level of thermal conductivity, a low coefficient of thermal expansion and a high recrystallization temperature. MHC retains its shape even when used at temperatures of up to 1550 °C. See the chemical composition and physical properties of Molybdenum-Hafnium-Carbon ...

Tensile and Stress-Rupture Behavior of Hafnium Carbide …

Three molybdenum alloy wires; Mo + 1.1 wt% hafnium carbide (MoHfC), Mo + 25 wt% W + 1.1 wt% hafnium carbide (MoHfC+25W) and Mo + 45 wt% W + 1.1 wt% hafnium …

Strain induced decomposition and precipitation of carbides …

Based on the chemical composition (see Table 1), the peaks with lower intensity can be identified as monoclinic hafnium dioxide (HfO 2), hexagonal molybdenum carbide (Mo 2 C) and face centered cubic hafnium carbide (HfC) [25], [26], [27]. The peaks with higher intensity are related to the matrix of the material (2θ: 40.5°, 58.6° and …

Creep behavior of molybdenum and a molybdenum-hafnium carbide …

DOI: 10.1016/0921-5093(94)90481-2 Corpus ID: 136887185; Creep behavior of molybdenum and a molybdenum-hafnium carbide alloy from 1600 to 2100 K @article{Luo1994CreepBO, title={Creep behavior of molybdenum and a molybdenum-hafnium carbide alloy from 1600 to 2100 K}, author={Anhua Luo and J. J. Park and …

Hafnium, Hf, atomic number 72 | Institute for Rare Earths …

It is therefore possible to use hafnium in flash lamps with a particularly high luminous efficiency. Several very stable and high-melting compounds, especially hafnium nitride and hafnium carbide, can be made from the elements. In alloys with metals such as niobium, tantalum, molybdenum and tungsten, an addition of 2% hafnium increases the ...

Hardening of molybdenum by microadditions of hafn-ium and HfC carbide

Hardening of molybdenum by microadditions of hafn-ium and HfC carbide. Scientific and Technical Section. Published: July 1974. Volume 6, pages 850–855, ( 1974 ) Cite this article. Download PDF. I. S. Malashenko,

Carbon – Hafnium – Molybdenum | Semantic Scholar

Carbon – Hafnium – Molybdenum. Mo-based alloys are of interest since they can satisfy a requirement such as the high-temperature operation with minimum deformation over a long time. The earlier work [1966Ord] considers the interaction of Mo with the HfC carbide that is studied over wide composition and temperature ranges; interactions ...

Structure-Process-Property-Performance Relations of …

Structure-Process-Property-Performance Relations of Tungsten and Molybdenum Refractory Alloys with Hafnium Carbide Additions Fabricated via Field Assisted Sintering Technology (FAST) ... The research then examined the effect of hafnium carbide (HfC) as a grain refiner in low concentrations (1, 3, 5 wt. %) by characterizing …

Creep behavior of molybdenum and a molybdenum-hafnium carbide …

The creep behavior of arc-melted molybdenum-0.5% hafnium carbide and commercial purity molybdenum was evaluated at temperatures from 1600 to 2100 K while subjected to stresses of 10–60 MPa in a vacuum below 1.3 × 10 −6 Pa (1.0 × 10 −8 Torr). The effects of temperature and stress on the steady-state creep rate of these …

Metallographic characterization of the molybdenum …

However, after the sintering process a thermo-mechanical treatment is applied to obtain the required properties. The microstructure of the sintered condition consists of strength increasing hafnium carbides (HfC). Additionally, a molybdenum carbide phase (Mo 2 C) is occurring in molybdenum-rich alloys of the Mo–Hf–C system …

EJM

Here we propose a new method to quantitatively impose fO2 in hydrous high-P–T experiments in molybdenum hafnium carbide (MHC) pressure vessels by admixing small amounts of hydrogen into the Ar pressure medium. The thermodynamic calculation procedure used to determine the initial amount of hydrogen to be loaded to constrain …

Tantalum Hafnium Carbide: Defying Extreme Conditions

Tantalum Hafnium Carbide (Ta4HfC5) stands as an exceptional material. It demonstrates unparalleled resilience in the face of extreme conditions. These extraordinary properties have made it essential across diverse industries. These features range from defying extreme temperatures with a remarkable melting point to exhibiting remarkable resistance.

Fabrication of molybdenum carbide and hafnium carbide …

We report on a process for the fabrication of Mo 2 C and HfC refractory metal carbide field emitter arrays using a modified Spindt tip fabrication process. Measurements of the aspect ratios of emitter cones showed that Mo 2 C tip structures have an aspect ratio similar to Mo field emitter tips. Where as with HfC, tip structures with a higher aspect …

Inserts for extrusion dies | Plansee

Molybdenum-hafnium carbide (MHC) is particularly temperature-resistant, has a high thermal conductivity and a low coefficient of expansion. MHC retains its shape even at operating temperatures up to 1550°C. MHC is suitable for use in die inserts for temperatures up to 800°C. At higher temperatures, we recommend using MHC for full dies.

Insights into the Bond Behavior and Mechanical Properties of Hafnium …

Hafnium carbide (HfC) is a potential candidate of ultrahigh-temperature ceramics (UHTCs) and has attracted significantly widespread interest in recent years. Here, we have synthesized high-purity HfC samples with NaCl-type structure by using a high-pressure solid–solid reaction. The structural stability, equation of state, plastic deformation, yield …

EJM

Here we propose a new method to quantitatively impose fO2 in hydrous high-P–T experiments in molybdenum hafnium carbide (MHC) pressure vessels by admixing small amounts of hydrogen into the Ar pressure …

Creep behavior of molybdenum and a molybdenum-hafnium carbide alloy

The creep behavior of arc-melted molybdenum-0.5% hafnium carbide and commercial purity molybdenum was evaluated at temperatures from 1600 to 2100 K while subjected to stresses of 10–60 MPa in a vacuum below 1.3 × 10 −6 Pa (1.0 × 10 −8 Torr). The effects of temperature and stress on the steady-state creep rate of these materials …

MHC (Molybdenum Hafnium Carbon) Alloy

MHC (Molybdenum Hafnium Carbon) Alloy. TZM & MHC & MoLa Rods Video - AEM Metal. Watch on. MHC alloy is the upgraded TZM alloy product, with superior performance and strength compared to TZM alloy. The new MHC alloy developed by AEM, with oxygen content less than 50ppm, can substitute TZM ally to achieve better efficacy.

Insights into the Bond Behavior and Mechanical Properties of Hafnium

Hafnium carbide (HfC) is a potential candidate of ultrahigh-temperature ceramics (UHTCs) and has attracted significantly widespread interest in recent years. Here, we have synthesized high-purity HfC samples with NaCl-type structure by using a high-pressure solid-solid reaction. The structural stability, equation of state, plastic …

Tensile and Stress-Rupture Behavior of Hafnium …

Three molybdenum alloy wires; Mo + 1.1 wt% hafnium carbide (MoHfC), Mo + 25 wt% W + 1.1 wt% hafnium carbide (MoI-IfC+25W) and Mo + 45 wt% W + 1.1 wt% hafnium carbide (MoHfC+45W), and a W + 0.4 wt% hafnium carbide (WHfC) tungsten alloy wire were evaluated. The tensile strength of all wires studied was found to have a positive …

Mechanical properties of molybdenum containing MoO2 …

The hafnium carbide powder (12.2 g/cm 3) (Reade Advanced Materials, Newton, MA) had a purity of 99% with average particle diameters between 1 μm and 3 μm. FAST processing. In the nominally pure molybdenum sample, in addition to BCC molybdenum, XRD identified MoO 2, as shown in Fig. 4a; MoO 2 particles are labeled …

High-temperature tensile properties of molybdenum and a molybdenum …

High-temperature tensile properties of molybdenum and a molybdenum-0.5%hafnium carbide alloy. ... Hafnium carbide (HfC), a compound with a NaCI structure and the highest melting temperature (4163 K) among all carbides, is an ideal strengthener to Mo. Previous study has shown that dispersed HfC particles could increase the …

MOLYBDENUM HAFNIUM CARBIDE POWDER …

The chemical composition of the molybdenum blended powder used for manufacturing the wrought bar shall conform to the following limits: Mo(Balance) Ni max. 0.005 % Si max. 0.005 % Fe max. 0.010 % C 0.05 - 0.15 % Hafnium 0.8 - 1.4 % Structure The MHC alloy bars can be supplied in the recrystallized condition upon request.

Solid solution hardening of molybdenum–hafnium alloys …

Abstract. In the present work the solid solution hardening (SSH) of the molybdenum–hafnium system (0.30–2.9 at% Hf) was investigated over the temperature range 448–1073 K. Particular attention was given on the manufacturing of the alloys in order to determine the critical resolved shear stress without the contribution of additional ...

Molybdenum Alloys | Molybdenum Hafnium Carbide (MHC…

Molybdenum Hafnium Carbide (MHC) is available in the following forms - Bar. Molybdenum Hafnium Carbide (MHC) Articles. Molybdenum Hafnium Carbide (MHC) Alloy; Request a Quote Suppliers of Molybdenum Hafnium Carbide (MHC) H.C. Starck Solutions; Newton, MA, United States

Carbon – Hafnium – Molybdenum

decrease as hafnium substitutes for molybdenum and also as the carbon content of the carbide increases [1975Ere3]. According to [ 1975Ere3], the width of the homogeneity …