Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Network Covalent Solids02:18

Network Covalent Solids

Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
Bonding and Strength of Aggregate01:12

Bonding and Strength of Aggregate

The bond between aggregate particles and the cement matrix is significantly influenced by the shape and surface texture of the aggregates. High-strength concretes benefit from a rougher texture, which leads to stronger bonding due to greater adhesion. Angular aggregates with larger surface areas also enhance this bond. The bonding quality, however, is complex to assess as no universally accepted test exists. Good bonding is indicated when a crushed concrete specimen shows some aggregate...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
Valence Bond Theory02:42

Valence Bond Theory

Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Covalent Bonds01:29

Covalent Bonds

When two atoms share electrons to complete their valence shells they create a covalent bond. An atom’s electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.A Covalent...
Bonding in Metals02:32

Bonding in Metals

Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Chemistry of energetic atoms produced by nuclear reactions.

Journal of the American Chemical Society·2010
Same author

Community pharmacist interventions in a capitated pharmacy benefit contract.

American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists·1998
Same author

Inhibition of erythrocyte phosphate transport by high pressures.

Proceedings of the National Academy of Sciences of the United States of America·1976
Same author

Climatology conference.

Science (New York, N.Y.)·1976
Same author

Letter: Temperature-dependent high-pressure argon effect on the radiolysis of water.

Radiation research·1976
Same author

Geographical coincidence of high heat flow, high seismicity, and upwelling, with hydrocarbon deposits, phosphorites, evaporites, and uranium ores.

Proceedings of the National Academy of Sciences of the United States of America·1974

Related Experiment Video

Updated: Jul 11, 2026

Fused Filament Fabrication (FFF) of Metal-Ceramic Components
08:43

Fused Filament Fabrication (FFF) of Metal-Ceramic Components

Published on: January 11, 2019

Sintered diamond compacts with a cobalt binder.

H Katzman, W F Libby

    Science (New York, N.Y.)
    |June 11, 1971
    PubMed
    Summary

    This study explored how to make the hardest diamond composites using cobalt as a binder. Researchers found that sintering diamond powder with 20% cobalt at 62 kilobars and 1570–1610 degrees Celsius produced the strongest results. The best hardness was achieved when diamond particles were 1 to 5 micrometers in size. These findings could help improve industrial tools that require high hardness and durability.

    Keywords:
    sintered diamondcobalt bindermicrohardnesshigh-pressure sintering

    Frequently Asked Questions

    More Related Videos

    Negative Additive Manufacturing of Complex Shaped Boron Carbides
    06:45

    Negative Additive Manufacturing of Complex Shaped Boron Carbides

    Published on: September 18, 2018

    Synthesis and Microdiffraction at Extreme Pressures and Temperatures
    07:26

    Synthesis and Microdiffraction at Extreme Pressures and Temperatures

    Published on: October 7, 2013

    Related Experiment Videos

    Last Updated: Jul 11, 2026

    Fused Filament Fabrication (FFF) of Metal-Ceramic Components
    08:43

    Fused Filament Fabrication (FFF) of Metal-Ceramic Components

    Published on: January 11, 2019

    Negative Additive Manufacturing of Complex Shaped Boron Carbides
    06:45

    Negative Additive Manufacturing of Complex Shaped Boron Carbides

    Published on: September 18, 2018

    Synthesis and Microdiffraction at Extreme Pressures and Temperatures
    07:26

    Synthesis and Microdiffraction at Extreme Pressures and Temperatures

    Published on: October 7, 2013

    Area of Science:

    • Materials science and engineering
    • Ceramic and composite materials
    • High-pressure materials synthesis

    Background:

    Current research in composite materials explores ways to strengthen diamond-based structures. Prior work has shown that diamond powders can be combined with metal binders to form durable composites. However, the precise conditions for optimal sintering remain unclear. No prior work had resolved how cobalt content and particle size affect the resulting hardness. This gap motivated investigations into the sintering process under high pressure. That uncertainty drove the need to test different cobalt concentrations and diamond grain sizes. It was already known that cobalt can act as a binder for diamond particles. But the exact temperature and pressure ranges for effective sintering were not fully established. This study aimed to clarify these parameters to improve the performance of diamond composites.

    Purpose Of The Study:

    The goal of this work was to determine the best conditions for sintering diamond with cobalt as a binder. Researchers wanted to identify the temperature and pressure that produce the strongest composite. They also sought to find the ideal cobalt concentration and diamond particle size. The motivation came from the need to improve the hardness of diamond composites. Existing methods lacked precise guidelines for sintering under high pressure. The study focused on how varying cobalt content affects the final product. By testing different mixtures, the team aimed to maximize microhardness. This approach could lead to better materials for industrial cutting and drilling.

    Main Methods:

    The study used high-pressure sintering techniques to bond diamond particles with cobalt. Diamond powders of different sizes were mixed with varying cobalt percentages. The mixtures were placed in a press and subjected to 62 kilobars of pressure. Temperatures ranged from 1570 to 1610 degrees Celsius during sintering. The resulting compacts were analyzed for microhardness. Researchers measured hardness using the Knoop scale. They tested multiple samples with different cobalt concentrations. The goal was to find the combination that produced the highest hardness.

    Main Results:

    The highest microhardness was observed at 3000 kilograms per square millimeter. This value was measured using the Knoop scale. The optimal cobalt content was 20 percent by volume. Diamond particles between 1 and 5 micrometers in size yielded the best results. Sintering occurred successfully at 62 kilobars of pressure. The temperature range for effective sintering was 1570 to 1610 degrees Celsius. Lower cobalt concentrations produced less hard composites. Larger diamond particles reduced the final hardness of the compact.

    Conclusions:

    The authors found that 20 percent cobalt and 1 to 5 micrometer diamond particles produced the hardest compact. They observed that sintering at 62 kilobars and 1570 to 1610 degrees Celsius was effective. The study suggests that cobalt content and particle size are important factors. These findings align with the hypothesis that smaller particles enhance hardness. The results support the use of cobalt as a binder in diamond composites. The authors propose that further testing could refine these parameters. Their findings may help improve industrial diamond tools. The study confirms that precise conditions are necessary for optimal sintering.

    The maximum microhardness of 3000 kg/mm² on the Knoop scale was achieved with 20% cobalt and 1–5 µm diamond particles.

    Cobalt was selected because it can effectively bond diamond particles under high pressure and temperature.

    Smaller particles increased the compact's hardness, as shown by the observed microhardness values.

    The Knoop scale was used to measure and compare the microhardness of the sintered diamond compacts.

    This pressure level is necessary for effective sintering of diamond and cobalt mixtures.

    The study may improve the design of diamond tools by optimizing binder and particle size for maximum hardness.