> ## Content Index > Fetch the complete content index at: https://clever-new-stuff.ghost.io/llms.txt > Use this file to discover other available public pages before exploring further. # Superhard carbon coating pushed to 100 micrometers, five times the previous best - URL: https://clever-new-stuff.ghost.io/superhard-carbon-coating-pushed-to-100-micrometers-five-times-the-previous-best/ - Published: 2026-10-18T12:31:41.000Z - Updated: 2026-10-18T12:31:41.000Z - Description: Researchers report having made a ta-C coating more than 100 micrometers (µm) thick. Ta-C is the hardest grade of diamond-like carbon. - Author: CNS Staff ###### ###### MATERIALS AND MANUFACTURING ### Superhard carbon coating pushed to 100 µm, 5x the previous best Researchers report having made a ta-C coating more than 100 micrometers (µm) thick. Ta-C is the hardest grade of diamond-like carbon. Coatings of this grade are usually a few micrometers thick, and the thickest reported before reached about 20 µm. The authors, from Fraunhofer IWS and TU Dresden, claim the thick coating keeps hard particles from denting the steel underneath, which is how thin hard coatings usually fail. The test involved pressing a diamond ball into coated bearing steel (100Cr6, also sold as 52100) under a 100 N load. A standard 1.5 µm coating cracked, and the steel under it deformed, leaving no protection. The 113 µm coating showed only fine cracks, with almost no deformation in the steel. In a scratch test at up to 90 N, the damage stayed within the thick coating, and the diamond tip broke. At about 15 times the load (1,474 N, the load used in the standard adhesion test), both coatings cracked, but the authors report the thick one still gave the steel substantial support. Neither coating peeled away from the steel in any test. The authors credit their pulsed laser-arc deposition process, which leaves less built-in stress in the coating: 1.6 gigapascals (GPa), against up to 10 GPa usual for ta-C. Built-in stress is what normally makes thick hard coatings crack or peel. Hardness was about 42 GPa in the thick coating and 47 GPa in the thin one; by the ISO definition, ta-C must reach 40 GPa. The steel stayed below 120 °C during coating, so it was not softened, as hardened steel is by the 400–700 °C needed to grow thick diamond films. **The limits.** The tests measured load-bearing only, with no wear, friction or service tests. The thick coating is rough (surface roughness about 0.83 µm, against 0.009 µm for the thin one) and was polished flat before the scratch tests. The authors give no coating time or cost. Their estimate that 65 µm would fully protect this steel at 100 N comes from a simplified model they call a rough estimate. Flat samples only. **Read the paper:** "Superhard and Hydrogen-Free Amorphous Carbon Coatings With Over 100 µm Thickness," *Advanced Functional Materials* (2026). [DOI: 10.1002/adfm.78864](https://doi.org/10.1002/adfm.78864?ref=clever-new-stuff.ghost.io) · [Free PDF](https://doi.org/10.1002/adfm.78864?ref=clever-new-stuff.ghost.io) --- ###### MATERIALS AND MANUFACTURING ### Fast cold drawing gives fine copper-silver wire 1 GPa strength at 89.5% of copper's conductivity Researchers report drawing a copper alloy with 2% silver down to 20 µm wire with a tensile strength of 1,076 megapascals (MPa) and an electrical conductivity of 89.5% IACS (the International Annealed Copper Standard, which rates pure annealed copper at 100%). Adding strength to copper wire normally costs conductivity, because the defects that strengthen the metal also scatter electrons. The authors say few low-silver copper alloys reach both 1,000 MPa and 85% IACS. They are from Henan Polytechnic University, South China University of Technology and three Chinese industrial research companies, among them China GRINM Group. The starting material was commercial cold-drawn Cu-2Ag wire, 900 µm across. It was pulled through 32 dies at drawing speeds of 300–700 m/min, each pass cutting the cross-section by about 25%, for a total reduction of 99.95%. Strength nearly doubled over the starting wire. Conductivity first fell as the wire thinned, then recovered to its peak at 20 µm. The authors trace the recovery to a change inside the metal at very high strain: the grains become fine fibers 20–100 nanometers wide, along with fine layered bands and twin boundaries, and fewer boundaries lie across the direction of current. Low silver content keeps cost down, the authors note, and copper wires of this kind are used for signal transmission. **The limits.** The headline figures hold for the 20 µm wire only. The tests covered tensile strength and conductivity, not fatigue, bending or long production runs. The figures for the starting wire came from its manufacturer. **Read the paper:** "Microstructure evolution and strength–conductivity synergy in Cu–2Ag alloy wires induced by high-speed large-deformation cold drawing," *Materials Science & Engineering A* (2026). [DOI: 10.1016/j.msea.2026.151206](https://doi.org/10.1016/j.msea.2026.151206?ref=clever-new-stuff.ghost.io) · [Free PDF](https://www.sciencedirect.com/science/article/pii/S0921509326014863/pdf?ref=clever-new-stuff.ghost.io) --- ###### ENERGY AND GRID ### Water-based binder replaces PVDF in lithium-ion electrodes and lets them be recycled directly Researchers report a binder for lithium-ion battery electrodes that is made without fluorine and mixed in water, replacing the PVDF binder and the toxic solvent NMP that most cell makers use today. LFP (lithium iron phosphate) cathodes made with it held 75.7% of their capacity after 1,000 cycles, and the authors say they lost capacity more slowly than PVDF-bound controls, especially after 400 cycles. Spent electrodes could be regenerated without fluorinated residue and performed like fresh material. The authors are from the University of California San Diego and the Toyota Research Institute of North America. The binder combines two polymers already made at scale for packaging and coatings, polyacrylic acid and carboxymethyl cellulose, linked by citric acid. Starting capacity matched PVDF: 160.2 against 160.5 mAh/g. Electrodes survived tape-peel and twisting tests that stripped material from PVDF electrodes. The binder also worked with other common electrode materials: LMFP, nickel-rich NCM811, graphite and silicon. A single-layer graphite–LFP pouch cell kept 76.4% of its capacity over 1,600 cycles. A multi-layer pouch cell kept 74.5% over 700 cycles, against 83.5% for the single layer at the same count. The authors' life-cycle and cost analysis puts manufacturing emissions 6.9% lower and energy use 9.3% lower than for PVDF-based cells, at $17.7 a cell, mainly because no NMP has to be recovered. **The limits.** The authors call the life-cycle figures indicative of trends, not industrial benchmarks. The cells are laboratory pouch cells, and the long cycling ran at moderate rates near room temperature. Two authors are named on a patent application for the binder. **Read the paper:** "Fluorine-free polymer binder enables circular manufacturing and recycling of lithium-ion batteries," *Nature Communications* (2026, article in press). [DOI: 10.1038/s41467-026-78215-3](https://doi.org/10.1038/s41467-026-78215-3?ref=clever-new-stuff.ghost.io) · [Free PDF](https://www.nature.com/articles/s41467-026-78215-3%5Freference.pdf?ref=clever-new-stuff.ghost.io) --- ###### ENERGY AND GRID ### White coating could let overhead lines carry 6–10% more current in hot cities, by the authors' model Researchers report a white coating for overhead power cables that reflects sunlight and sheds heat, and calculate that it could raise a line's current-carrying capacity (its ampacity) by 6–10% in hot-climate cities. Line temperature limits how much current a line may carry, so a cooler line can carry more without new conductors. The authors are from King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. The coating is silicone rubber (PDMS) filled with hexagonal boron nitride particles. It reflects 92% of sunlight, radiates heat strongly at infrared wavelengths, and conducts heat better than ordinary cable insulation. On three commercial steel-reinforced aluminum (ACSR) cables hung outdoors without current, the coated one ran about 5 °C cooler than the bare one and about 15 °C cooler than a black insulated one at midday sun of about 1,100 W/m². Simulated cables heated from inside by resistance wire stayed about 5 °C below the 75 °C operating limit over a week in August. For a common ACSR conductor under the CIGRE 601 rating method, the calculated ampacity rose to 830 A, against 710 A bare and 630 A insulated. The coating kept its reflectance after 240 hours of accelerated UV aging, and passed sand-abrasion, salt-spray and flame tests. **The limits.** The ampacity gains are calculated, not measured on a line in service. The current-carrying tests used simulated cables, and the outdoor tests ran for a week at one site. The authors call the coating retrofittable but do not show it applied to a working line. It was tested at 2 mm thick, and the paper does not address the added weight. **Read the paper:** "Photonic thermal management of overhead cables via high-thermal-conductivity radiative cooling," *Light: Science & Applications* (2026). [DOI: 10.1038/s41377-026-02485-1](https://doi.org/10.1038/s41377-026-02485-1?ref=clever-new-stuff.ghost.io) · [Free PDF](https://www.nature.com/articles/s41377-026-02485-1.pdf?ref=clever-new-stuff.ghost.io) --- ###### PROCESS AND CHEMICALS ### Milling magnesium oxide while it captures CO2 raises uptake 6x Researchers report that grinding magnesium oxide (MgO) in a ball mill while it is exposed to CO2 raises the amount of CO2 it captures six-fold, compared with leaving the same powder in CO2 without milling. Adding moisture, as in real flue gas, doubled uptake again. MgO is cheap and releases captured CO2 at lower temperatures than the calcium oxide used in some capture systems, but a carbonate crust forms on its surface and stops further uptake. The authors, from the Max-Planck-Institut für Kohlenforschung in Germany, say milling keeps breaking that crust. The tests used commercial MgO powder in a laboratory mixer mill at 20 Hz, under simulated flue gas (10% CO2 at 40 °C). With moisture and 8 hours of milling, the powder held 295.3 mg of CO2 per gram, which the authors say is the highest value reported for MgO. Over ten capture-and-release cycles, with release by heating to 600 °C, uptake averaged 17.4% by weight with no sign of damage to the material. Ball size, ball material and milling frequency all changed the result. **The limits.** Gram-scale tests in a laboratory mill. The paper does not cost the energy used in milling, which an industrial process would have to pay for. At high milling frequencies the jar and balls wore, contaminating the powder. Release required heating to 600 °C each cycle. **Read the paper:** "Increasing the (Re)Activity of MgO for Carbon Capture under Continuous Ball Milling," *Chemistry of Materials* (2026). [DOI: 10.1021/acs.chemmater.6c01597](https://doi.org/10.1021/acs.chemmater.6c01597?ref=clever-new-stuff.ghost.io) · [Free PDF](https://pubs.acs.org/cmatex/article-pdf/doi/10.1021/acs.chemmater.6c01597/68781454/acs.chemmater.6c01597.pdf?ref=clever-new-stuff.ghost.io) --- ###### INSTRUMENTATION AND MEASUREMENT ### Ferrite cores let a rotating eddy-current probe find flaws 6 mm below the surface Researchers report an eddy-current inspection probe that finds cracks of any orientation buried up to 6 mm below the surface of aluminum plate, where the same probe without ferrite cores found nothing. Eddy-current testing usually faces two trade-offs. A probe sees cracks lying across its induced currents better than cracks along them, and lowering the frequency to see deeper weakens the signal. Rotating-field probes solve the first; adding ferrite cores to concentrate the field addresses the second. The authors, from Sapienza University of Rome and two other Italian universities, say earlier ferrite-core rotating probes were tested only on surface cracks. The four-coil probe was tested on aluminum alloy 6082 plates, 4 mm and 10 mm thick, with machined slots, at 500 Hz and 200 Hz. Against an identical probe with air cores, the ferrite version gave signals about 22–26% stronger on the thinner plate. On the thicker plate the gain grew with depth, passing 100% for the deepest flaws, and the deepest one was detected only with ferrite. **The limits.** Two aluminum plates with machined slots, not real cracks, and no ferrous metals. The authors say their detection depths cannot be ranked against other studies because materials, flaw shapes and frequencies differ. Measured gains differed from their simulations, which they attribute to sensor noise and manufacturing tolerances. **Read the paper:** "Ferrite-Core Four-Quadrant Rotating Eddy Current Probe for Enhanced Subsurface Defect Detection of Any Orientation," *Sensors* (2026). [DOI: 10.3390/s26206495](https://doi.org/10.3390/s26206495?ref=clever-new-stuff.ghost.io) · [Free full text](https://doi.org/10.3390/s26206495?ref=clever-new-stuff.ghost.io) --- ###### OFFBEAT ### A pendulum shows where a bicycle chain loses its energy Researchers built a pendulum that swings on a short length of bicycle chain wrapped over a sprocket, and timed how fast the swing died away. The faster it stops, the more energy the chain's joints lose to friction. The inner links lost 35–50% more than the outer links. A wax-based lubricant cut losses by about 10–20% on a conventional bushed chain, more than on a modern bushingless 11-speed chain. Chain tension mattered little, and the two chain designs differed less than expected. The authors are from Griffith University in Australia and Ride Mechanic, an Australian maker of bicycle lubricants. Full drivetrain test rigs measure the losses of the whole system. This method isolates the joints, which the authors propose as a cheap way to compare lubricants and chains. **The limits.** Two chains, an IZUMI single-speed and a Shimano CN-HG701, three samples each, and one lubricant, which the paper does not name. Slow swings, not pedaling loads. **Read the paper:** "A pendulum-based experimental investigation of frictional behaviour in bushed and bushingless bicycle roller chains," *Tribology International* (2027). [DOI: 10.1016/j.triboint.2026.112815](https://doi.org/10.1016/j.triboint.2026.112815?ref=clever-new-stuff.ghost.io) · [Free full text](https://doi.org/10.1016/j.triboint.2026.112815?ref=clever-new-stuff.ghost.io)