Description:
Invention Summary
This invention is applicable to toughening diamonds—that is, to improvements in the wear resistance and/or hardness of natural or synthetic diamond. The treatment is an immersion of the diamond in a low-temperature plasma environment. The plasma cations penetrate into the diamond material. The small ion with an available reactive bond (because of its positive charge) may bond with the chemical structure in the diamond, particularly where reactive surfaces (along faults, cracks, inclusions, dislocations or occlusions), forming a covalent bond.
Market Opportunity
As there are few processes that can measurably improve the properties of diamonds, it would be desirable to find an alternative to the high temperature process. High temperatures are capable of worsening existent flaws in diamonds by strain on the diamond due to thermal expansion and expansion of gases within the diamond flaws, and by oxidation or other chemical changes in the diamond, especially on its surface. Applications include the following: treatment of die surfaces, diamond grit, diamond needles such as styli, micro-hardness indentors, and drilling bits. The process is preferred for use with synthetic diamonds, but may be used with natural diamonds. The size of the diamonds treated may also vary along a wide range, from powders or 5 micrometer average diameters up to larger size diamonds, without limit, although maximum average diameters of no more than 2 m.m. are more amenable to treatment by this process. Also, the method may be used to treat diamond powder, which may conveniently be treated by a plasma environment with or without vibration to ensure that all surfaces of the powder are treated.
Features & Benefits
•A diamond is treated to improve its physical properties through low temperature (that is defined as less than 300° C., preferably less than 200° C., and more preferably less than 100° C., including 0-70° C., and 15-50° C.) cationic plasma. The plasma preferably comprises low molecular elemental plasma such as H+
•The use of lower temperature plasma is believed to further lessen the potential damage to the diamonds and the functional action of the plasma (i.e., for example in covalently bonding into the diamond materials).
•The preferred form for working with diamond material is where the diamond is in the form of a powder. In treating a powder batch or continuous supply of powder diamonds, the powder may be vibrated during the treatment with the plasma to effect greater exposure of all surfaces of individual particles.
Intellectual Property Published Patent: US-2013-0330265-A1