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MgBi is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Mg is bonded in a 6-coordinate geometry to six equivalent Bi atoms. All Mg–Bi bond lengths are 3.16 Å. Bi is bonded in a 6-coordinate geometry to six equivalent Mg atoms.
MgSb is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Mg2+ is bonded in a 6-coordinate geometry to six equivalent Sb2- atoms. All Mg–Sb bond lengths are 3.04 Å. Sb2- is bonded in a 6-coordinate geometry to six equivalent Mg2+ atoms.
MoSe is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Mo2+ is bonded to six equivalent Se2- atoms to form a mixture of distorted edge, corner, and face-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.62 Å. Se2- is bonded in a 6-coordinate geometry to six equivalent Mo2+ atoms.
YbBr is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Yb is bonded in a 6-coordinate geometry to six equivalent Br atoms. All Yb–Br bond lengths are 3.11 Å. Br is bonded to six equivalent Yb atoms to form a mixture of distorted corner, edge, and face-sharing BrYb6 pentagonal pyramids.
LuTe is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Lu is bonded to six equivalent Te atoms to form a mixture of distorted edge, face, and corner-sharing LuTe6 pentagonal pyramids. All Lu–Te bond lengths are 3.06 Å. Te is bonded to six equivalent Lu atoms to form a mixture of distorted edge, face, and corner-sharing TeLu6 pentagonal pyramids.
HfS is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Hf is bonded to six equivalent S atoms to form a mixture of distorted corner, edge, and face-sharing HfS6 pentagonal pyramids. All Hf–S bond lengths are 2.61 Å. S is bonded to six equivalent Hf atoms to form a mixture of distorted corner, edge, and face-sharing SHf6 pentagonal pyramids.
PuCl is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Pu is bonded in a 6-coordinate geometry to six equivalent Cl atoms. All Pu–Cl bond lengths are 3.04 Å. Cl is bonded in a 6-coordinate geometry to six equivalent Pu atoms.
Sb2F11HF2 is Tungsten Carbide structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one hydrogen fluoride hydrogen fluoride molecule and one Sb2F11 cluster. In the Sb2F11 cluster, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Sb–F bond distances ranging from 1.89–2.08 Å. There are six inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Sb atom. In the second F site, F is bonded in a single-bond geometry to one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a single-bond geometry to one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a linear geometry to two equivalent Sb atoms.
The DOE has research interest in new technologies for high temperature concentrated solar power plants. Our project this summer was to explore the use of additively manufactured ultra-high-temperature ceramics in a heat exchanger. The heat exchanger would transfer heat between a molten chloride salt and supercritical CO 2 . We selected 22 compositions to test and were able to mix 14 of these compositions. We sintered these compositions using pressureless sintering and direct current sintering. We also conducted high temperature TGA on some ceramic samples. We also performed preliminary binder jet additive manufacturing trials with tungsten carbide powder. Our work so far points towards one of our titanium diboride samples being promising, but much more research needs to be done.
This report describes a collaborative project to develop a validated, predictive model for the high temperature mechanical properties of a titanium-matrix, tungsten-carbide/cobalt-reinforced metal matrix composite. The modeling approach was to first develop a detailed, microstructural model linking the material structure and the interfacial debonding properties to the effective properties of the material. The project then completed a throughput simulation campaign to generate a large number of simulations for discrete microstructures and different debonding parameters. Finally, the project trained a fast, Gaussian process surrogate model against this simulation database to provide a quick model linking the material compositions, structure, and processing parameters to the resulting material properties. This model was validated against high temperature tensile test data on a few particular composite compositions. The tests validate the model predictions for ultimate tensile strength and uniform elongation/ductility, meaning the final surrogate model can now be used to tune the material composition and processing parameters to identify optimal composite compositions for particular applications.
Process produces continuous internal channel systems on a repeatable basis in 2014-T6 aluminum. Standard machining forms the initial channel, which is filled with tungsten carbide powder. TIG machine fusion welding completes formation of the channel. Chem-mill techniques enlarge it to the desired size.
Precision tungsten carbide balls measure the internal angle of flared joints. Measurements from small and large balls in the flare throat to an external reference point are made. The difference in distances and diameters determine the average slope of the flare between the points of ball contact.
Tables on fracture mechanics of notched bars of boride composites and cobalt bonded tungsten carbide
Submicron sectioning apparatus for studying slow carbon self diffusion in dense polycrystalline tungsten carbide
Fracture energies of WC-6Co, Boride 5 (ZrB2+SiC), Boride 8(ZrB2+SiC+C) and Boride 8-M2(ZrB2+SiC+C) were measured by slow bend and impact tests of notched charpy bars. Cobalt bonded tungsten carbide exhibited impact energies of 0.76 ft-lb or 73.9 in-lb/square inch. Boride 5 and the Boride 8 exhibit impact energies one third and one quarter of that observed for WC-6Co comparing favorably with measurements for SiC and Si3N4. Slow bend-notched bar-fracture energies for WC-6Co were near 2.6 in-lb/square inch or 1/20 the impact energies. Slow bend energies for Boride 8-M2, Boride 8 and Boride 5 were 58%, 42% and 25% of the value observed for WC-6Co. Fractograph showed differences for WC-6Co where slow bend testing resulted in smooth transgranular cleavage while samples broken by impact exhibited intergranular failures. By contrast the boride fractures showed no distinction based on testing method. Fabrication studies were conducted to effect alteration of the boride composites by alloying and introduction of graphite cloth.
Plasma-arc spraying offers method of preparing required surface at greatly reduced cost. Coarse-grained, tungsten carbide bonded-nickel coating is applied by spraying. Coating has been used successfully on wedge-shaped mechanical test grips.
A valve apparatus capable of maintaining a fluid-tight seal over a relatively long period of time by releasably bonding a valve member to its seat is described. The valve member is bonded or welded to the seat and then released by the application of the same energy to the bond joint. The valve member is held in place during the bonding by a clamping device. An appropriate force device can activate the opening and closing of the valve member. Various combinations of material for the valve member and valve seat can be utilized to provide an adequate sealing bond. Aluminum oxide, stainless steel, inconel, tungsten carbide as hard materials and copper, aluminum, titanium, silver, and gold as soft materials are suggested.
A titanium - 6-percent-aluminum - 4-percent-vanadium alloy (Ti-6Al-4V) was subjected to fretting-wear exposures against uncoated Ti-6Al-4V as a baseline and against various coatings and surface treatments applied to Ti-6Al-4V. The coatings evaluated included plasma-sprayed tungsten carbide with 12 percent cobalt, aluminum oxide with 13 percent titanium oxide, chromium oxide, and aluminum bronze with 10 percent aromatic polyester; polymer-bonded polyimide, polyimide with graphite fluoride, polyimide with molybdenum disulfide (MoS2), and methyl phenyl silicone bonded MoS2, preoxidation surface treatment, a nitride surface treatment, and a sputtered MoS2 coating. Results of wear measurements on both the coated and uncoated surfaces after 300,000 fretting cycles indicated that the polyimide coating was the most wear resistant and caused the least wear to the uncoated mating surface.