WC-CrC-Ni (73/20/7) is the cobalt-free variant of WC-CoCr — the coating for parts that have to survive wet, salty, or mildly acidic service and a supply chain that cannot accept cobalt.

Seventy-three percent tungsten carbide, twenty percent chromium carbide, seven percent nickel. Swap the cobalt binder for nickel-chromium and the chemistry shifts. Twenty percent chrome in the binder, nickel in place of cobalt, a denser microstructure than WC-CoCr on the same gun. Peer-reviewed HVAF data show <0.1% porosity versus 0.8% for WC-CoCr on the same rig, about 15% better cavitation resistance, and comparable hardness around 1,100-1,200 HV.

We apply it by HVOF to marine hydraulic rods, offshore pump internals, downhole tooling in wet or sour service, chemical-process slurry pumps, pulp and paper rolls, and nuclear or food-contact parts where cobalt migration is a regulatory problem. Bond strength exceeds 10,000 psi. Porosity lands under one percent. Grinds to 2-4 µin Ra; superfinishes below 1 µin for dynamic seals. Service to 500°C safely.

Cross-referenced across industry as TAFA LW-105 / LW-105A, AMPERIT 551, Diamalloy 5846, PMET 73-20-7, WallCarb 73/20/7, and legacy RAM 25.

WC-CoCr (86/10/4) stays the default when corrosion is moderate and cobalt is fine. Specify this chemistry when cobalt has to go — or when the water is salt, the service is acidic, and the part needs to last.

Technical data

Hardness: 1000-1200 HV0.3 typical HVOF (peer-reviewed HVAF WC-20CrC-7Ni: 1160 ± 190 HV0.05); commercial datasheets (Cincinnati Thermal Spray CT2250-2) call 1,250-1,450 HV
Bond strength: >10,000 psi (69 MPa) typical HVOF; published research on WC-CrC-Ni reports ~73 MPa (10,600 psi); HVAF variants run higher on the same chemistry
Max service temp: 930°F (general WC oxidation ceiling) up to ~1,350°F per CTS datasheet in oxidizing but dry service
Max service temp: 500°C standard; up to ~730°C (CTS claim) in select oxidizing service — 500°C is the safe spec for wet/corrosive
As-sprayed porosity: <1% HVOF typical; peer-reviewed HVAF WC-20CrC-7Ni measured <0.1% versus 0.8% for WC-CoCr on the same rig
Typical thickness: 4-14 (100-350 µm); extended builds to 20+ mils (500+ µm) feasible for heavy-wear or rebuild work
Surface finish (Ra): 80-200 as-sprayed; 2-4 diamond-ground; superfinished to <1 µin for dynamic-seal surfaces

Where it earns its keep

Cobalt-free variant of WC-CoCr — drops the entire regulatory stack that sits on cobalt (REACH SVHC classification for cobalt metal, oral-carcinogen category, and any downstream OSHA/customer specifications that restrict cobalt in contact parts)
Twenty percent chromium plus a nickel binder beats WC-10Co-4Cr on corrosion in seawater, mildly acidic, and cavitation-rich service — published HVAF comparison shows ~15% lower volume loss under cavitation and ten-fold lower porosity (<0.1% vs 0.8%) on the same rig
Dense, hard, well-bonded cermet: <1% porosity HVOF and <0.1% HVAF, bond strength >10,000 psi, hardness 1,000-1,450 HV depending on process and grind — grinds to 2-4 µin Ra and superfinishes below 1 µin for dynamic seals
More ductile than WC-12Co on impact and thermal cycling, which matters on shock-loaded pump internals and large marine rams
Standard industry designation with multiple supply paths — AMPERIT 551 (Höganäs), PMET 73-20-7 (Polymet), Diamalloy 5846 / Sulzer Metco 5845 (Oerlikon Metco), WallCarb 73/20/7 (Wall Colmonoy), and the TAFA LW-105 family all target the same chemistry

Where it doesn't

Somewhat lower measured hardness than WC-12Co or WC-CoCr in the same process window — specify this coating when corrosion or cobalt-free drives the decision, not pure abrasion
Higher powder cost than WC-12Co — 20% chromium plus the nickel binder and the tighter particle distributions add up
Not the aerospace default — SAE ARP5935 / AMS 2447 landing-gear chrome-replacement spec is WC-Co and WC-CoCr; this chemistry is a niche pick, not a drop-in for qualified aerospace parts
Avoid nitric acid and very high pH service — the nickel binder has limits; for heavy oxidizing service above ~500°C, consider Cr3C2-NiCr instead
As with all WC cermets, watch decarburization at spray — HVAF and well-tuned liquid-fuel HVOF preserve the WC phase better than hot gas-fuel HVOF

Sources

Data points on this page draw on the following published references. Nothing here replaces a material-specific review by our process engineers — but it's the working starting point.

Cincinnati Thermal Spray — CT2250-2 High Density 73/20/7 WC-CrC-Ni HVOF Coating
“Nominal composition 73% WC – 20% Cr2C3 – 7% Ni; hardness Vickers 1,250-1,450; bond strength in excess of 10,000 psi; porosity less than 2%; service temperature up to 1,350°F; addresses severe service conditions of abrasive wear, hard surface wear, low temperature erosion and fretting; exhibits more ductility than Tungsten Carbide Cobalt coatings; use in any acids and alkalais where nickel can be used — avoid nitric acid.”
Höganäs AMPERIT 551 — WC-CrC-Ni 73/20/7, agglomerated and sintered
“WC-based agglomerated powder containing chromium carbide and nickel for good corrosion resistance; hard, dense coatings with excellent erosion, abrasion and sliding wear resistance; higher oxidation and corrosion resistance than WC-Co-Cr coatings.”
Polymet PMET 73-20-7 WC-20Cr-7Ni HVOF Powder Datasheet
“Spherical agglomerated-and-sintered 73WC-20Cr-7Ni for HVOF; ideal for a wide variety of erosive and abrasive wear applications; especially effective where the component is exposed to abrasive media; more ductility than tungsten-carbide-cobalt coatings.”
Journal of Thermal Spray Technology — Cavitation Resistance of WC-10Co4Cr and WC-20CrC-7Ni HVAF Coatings
“WC-CoCr coating had porosity of 0.8 ± 0.1%, while the WC-CrC-Ni coating contained less than 0.1% porosity; WC-20CrC-7Ni volume loss 6.2 mm³ vs 7.3 mm³ for WC-10Co4Cr after 330 minutes of cavitation testing; microhardness HV0.05 1160 ± 190 for WC-20CrC-7Ni vs 1170 ± 180 for WC-10Co4Cr.”
Microstructure characteristics and properties of WC-CrC-Ni HVOF coating for boiler tube steel
“WC-CrC-Ni HVOF coatings show bond strength of 73.13 MPa and microhardness of 1,093 HV with average porosity of 2.33%; suitable for solid particle impact wear above 673 K.”
Surface & Coatings Technology — Cobalt-free metallic binders for HVOF thermal sprayed wear-resistant coatings
“Three cermet HVOF coatings with different cobalt-free metallic binders evaluated as alternatives to WC-CoCr: WC-NiMoCrFeCo, WC-CrC-Ni, and WC-FeCrAl; urgent need to find substitutes for the traditional cobalt binder in WC-based metal-ceramic hard coatings.”
WC-CrC-Ni 73/20/7 Agglomerated and Sintered HVOF Powder Specification
“Agglomerated and sintered WC-20Cr3C2-7Ni: Ni 6-8%, Cr 20-23%, Fe ≤0.5%; apparent density >4.0 g/cm³; hard, dense coatings with excellent erosion, abrasion and sliding wear resistance; higher oxidation and corrosion resistance than WC-Co-Cr coatings; recommended for ball and gate valves, pump parts, paper, and petroleum machinery.”
HTS Coatings — Three Tungsten Carbide Thermal Spray Coatings and Their Uses
“Tungsten Carbide Nickel (90WC-10Ni) provides more corrosion resistance at lower hardness than WC-Co; the non-cobalt composition prevents degradation in radioactive environments; commonly applied to ball and gate valves.”
Journal of Marine Science and Engineering — Cavitation-Silt Erosion Behavior of HVOF-Sprayed WC-Cr3C2-Ni Coating for Offshore Hydraulic Machinery
“HVOF-sprayed WC-Cr3C2-Ni coating possesses superior cavitation-silt erosion resistance compared to 1Cr18Ni9Ti stainless steel across a range of flow velocities and sand concentrations relevant to offshore hydraulic service.”

Material data on this page is provided as a general reference and can vary by lot, substrate, and application. Contact HTS to confirm the right material and specification for your specific part.

Tungsten Carbide · Chrome · Nickel

Technical data

Where it earns its keep

Where it doesn't

Typical applications

Wear modes addressed

Industries

Substrates

Sources

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