Abstract: A system for additive manufacturing of a three-dimensional object includes a powder compaction apparatus having at least one compaction roller configured to spread and compact a powder material across a powder bed, and a printing apparatus configured to selectively bind or fuse the powder material. At least a portion of the at least one compaction roller is made from silicon carbide. The at least one compaction roller includes a work zone having a first end and a second end, a first bearing zone extending from the first end of the work zone, and a second bearing zone extending from the second end of the work zone. The work zone has a surface finish of less than 50 microinches Ra. At least one of the first bearing zone and the second bearing zone are formed monolithically with the work zone, or connected to the work zone via a joint.

Abstract: Diamond-containing articles such as composite materials shaped as some specific article, can be engineered such that bodies that contact the article only contact diamond. In an embodiment, the article may be in the form of equipment for handling semiconductor wafers such as vacuum or electrostatic chucks. In one embodiment, the diamond-containing article can be a composite of diamond particulate reinforcing a Si/SiC body such as reaction-bonded SiC. Lapping the diamond-reinforced RBSC body with progressively finer diamond grit removes some of the SiC/Si matrix material, leaving diamond particles of uniform height “standing proud” above the rest of the surface of the formed article. Further, if the diamond-containing article is sufficiently electrically conductive, it may be machinable using electrical discharge machining.

Abstract: A perforated film electrode for a pinned electrostatic chuck that lies below the top surface of the pins in the valleys or interstices between pins, below the elevation of the top surface of the pins, and is attached to the body of the chuck. In one embodiment, the perforated film electrode assembly features a thin film electrode sandwiched between thin sheets of electrically insulating material. The top, outer or exposed surface of the perforated film electrode assembly has a flatness that is maintained within 3 microns. That is, the distance or elevation between the tops of the pins and the top surface of the perforated film unit is maintained within plus or minus 3 microns. A tool for producing a uniform elevation of the top and bottom sheets or layers of electrically insulating material also is taught.

Abstract: Diamond-containing articles such as composite materials shaped as some specific article, can be engineered such that bodies that contact the article only contact diamond. In an embodiment, the article may be in the form of equipment for handling semiconductor wafers such as vacuum or electrostatic chucks. In one embodiment, the diamond-containing article can be a composite of diamond particulate reinforcing a Si/SiC body such as reaction-bonded SiC. Lapping the diamond-reinforced RBSC body with progressively finer diamond grit removes some of the SiC/Si matrix material, leaving diamond particles of uniform height “standing proud” above the rest of the surface of the formed article. Further, if the diamond-containing article is sufficiently electrically conductive, it may be machinable using electrical discharge machining.

Abstract: A perforated film electrode for a pinned electrostatic chuck that lies below the top surface of the pins in the valleys or interstices between pins, below the elevation of the top surface of the pins, and is attached to the body of the chuck. In one embodiment, the perforated film electrode assembly features a thin film electrode sandwiched between thin sheets of electrically insulating material. The top, outer or exposed surface of the perforated film electrode assembly has a flatness that is maintained within 3 microns. That is, the distance or elevation between the tops of the pins and the top surface of the perforated film unit is maintained within plus or minus 3 microns. A tool for producing a uniform elevation of the top and bottom sheets or layers of electrically insulating material also is taught.

Abstract: A composite material featuring comminuted or otherwise well dispersed and separated nanotubes reinforcing a matrix featuring metal, ceramic and/or polymer. In a preferred embodiment, the nanotubes feature elemental carbon, and the composites can be produced using a molten silicon metal infiltration technique, which may be pressurized or not, for example, a siliconizing or a reaction-bonding process. In this preferred embodiment, carbon nanotubes may be prevented from chemically reacting with the silicon infiltrant by an interfacial coating disposed between the carbon nanotubes and the infiltrant. A reaction-bonded composite body containing even a small percentage of carbon nanotubes possessed a significant increase in electrical conductivity as compared to a reaction-bonded composite not containing such nanotubes, reflecting the high electrical conductivity of the nanotubes.

Abstract: A composite material featuring carbon nanotubes reinforcing a matrix featuring metal or silicon carbide, or both. Such composites can be produced using a molten silicon metal infiltration technique, for example, a siliconizing or a reaction-bonding process. Here, the carbon nanotubes are prevented from chemically reacting with the silicon infiltrant by an interfacial coating disposed between the carbon nanotubes and the infiltrant. Preferably, the coating is free carbon or a carbonaceous precursor material added during preform processing, or after. The reaction-bonding system is designed such that the molten infiltrant of silicon metal or silicon alloy reacts with at least some of the interfacial carbon layer to form in-situ silicon carbide, and that the formed SiC is sufficiently dense that it effectively seals off the underlying carbon nanotube from exposure to additional molten infiltrant.