MCrAlY nickel-base — nominally Ni-22Cr-10Al-1Y — is the coating that lets a turbine blade survive the fire inside a combustion chamber. This is the bond coat under yttria-stabilized zirconia (YSZ) thermal-barrier coatings, and it's also the standalone hot-corrosion overlay for industrial gas-turbine blades where no ceramic top coat is specified. Cross-references on the print: Oerlikon Metco Amdry 962, Höganäs AMPERIT 410-series, Metco 461NS.

It works by growing a self-healing α-Al₂O₃ (alumina) scale at temperature. The ~1% yttrium addition is the decisive ingredient — it pegs the alumina to the substrate under thermal cycling, the 'reactive-element effect' that defines the MCrAlY family. Chromium contributes a secondary Cr₂O₃ scale that defeats hot corrosion and sulfidation. NASA Glenn's late-1970s flight-rig work established the two-layer NiCrAlY-plus-YSZ architecture still flying today.

At HTS we apply MCrAlY by HVOF for dense (<2% porosity, ~54 MPa bond) standalone overlays, and by atmospheric plasma spray for TBC bond coats where surface roughness helps the ceramic key in. Service temperature 980-1050°C on the bond coat. Typical thickness 3-10 mils under YSZ, 10-20 mils standalone. This is not a wear coating — for abrasion resistance, pick WC-Co. If you have a turbine blade, vane, or combustor liner that needs to live above 900°C, send us the drawing.

Technical data

Hardness: HVOF typ. 450-490 HV as-sprayed (measured 486 HV in peer-reviewed HVOF study); APS typ. 330-420 HV as-sprayed, rising to ~371 HV after 1100°C diffusion heat treatment. Hardness is a byproduct — this is not a wear coating.
Bond strength: HVOF ~7,800 psi (54 MPa) as-sprayed; APS ~4,900 psi (34 MPa) as-sprayed, rising to ~9,000 psi (62 MPa) after 1100°C diffusion heat treatment. Comfortably clears the 5,000 psi (~34 MPa) bond-coat threshold.
Max service temp: 1800°F (980°C) oxidation limit when applied by atmospheric plasma spray; 1920°F (1050°C) by HVOF or controlled-atmosphere plasma per Oerlikon Metco. Thermal-shock rigs have demonstrated YSZ/NiCrAlY systems surviving 1242 cycles at 1200°C and 800h isothermal at 1150°C before spallation.
Max service temp: 980°C (APS) / 1050°C (HVOF or LPPS/VPS); TBC system operates hotter at the YSZ surface with the bond coat sitting below the oxidation limit.
As-sprayed porosity: HVOF ~1.5-2% (measured 1.56 vol% in peer-reviewed study); APS ~3-6% as-sprayed, densifying to ~1.6% as the thermally grown oxide (TGO) fills inter-lamellar voids in service. Controlled-atmosphere plasma (LPPS/VPS) hits <1%.
Typical thickness: 3-10 mils (75-250 µm) as TBC bond coat under YSZ; 10-20 mils (250-500 µm) as a standalone hot-corrosion overlay on industrial gas turbine blades and vanes. Diffusion heat treatment post-spray is standard for aerospace duty.

Where it earns its keep

Forms a protective α-Al₂O₃ scale at temperature that is self-healing — scratches and spallation re-oxidize back to continuous scale
Yttrium addition (~1 wt%) dramatically improves alumina scale adherence under thermal cycling — the 'reactive-element effect' that defines the MCrAlY family
Chromium contributes a secondary Cr₂O₃ scale that resists hot corrosion and sulfidation in contaminated fuel environments
Decades of qualified aerospace flight service under OEM proprietary specs (Pratt & Whitney, GE, Rolls-Royce)
HVOF deposition gives dense (<2% porosity), well-adhered (54-62 MPa) bond coats that outperform APS for oxidation resistance
Thermodynamically compatible with YSZ top coat — the alumina TGO is the chemically stable interface zirconia grows against

Where it doesn't

This is a BOND COAT or standalone hot-corrosion OVERLAY — not a wear coating. Do not specify MCrAlY for abrasion, erosion, or sliding-wear duty; choose WC-Co or chromium-carbide NiCr instead.
TBC service life is ultimately limited by TGO growth at the MCrAlY / YSZ interface — oxide scale thickness at spallation is the dominant failure criterion.
Diffusion heat treatment (typically 1080-1120°C in vacuum or argon) is standard for aerospace duty: it homogenizes the β-NiAl / γ-Ni phase structure, densifies porosity, and maximizes bond strength.
HVOF deposition produces denser, more adherent coatings than APS but with a finer particle-size cut and stricter parameter control; LPPS/VPS is the aerospace gold standard where porosity must be <1%.
Proprietary aerospace OEM specifications (PWA, B50, MSRR) usually govern qualification — public AMS numbers alone are rarely sufficient for flight hardware.
Service-temperature limit (980-1050°C on the bond coat itself) sets the upper bound; YSZ top coat allows the gas-path surface to run hotter while the metal sits below.

Which process, when?

HVOF is the dense, high-bond-strength choice for MCrAlY: ~1.5-2% porosity, 54 MPa as-sprayed bond strength, ~486 HV hardness. Best for standalone overlay duty and for bond coats where oxidation life is the priority. Atmospheric plasma spray (APS) is the workhorse for TBC bond coats under YSZ — higher as-sprayed porosity (3-6%) and lower bond strength (~34 MPa) than HVOF, but the controlled roughness at the bond-coat surface is what the ceramic top coat mechanically keys into. Post-spray diffusion heat treatment at 1080-1120°C recovers APS properties (porosity drops to ~3%, bond strength rises to ~62 MPa, hardness to ~371 HV). Low-pressure (LPPS) / vacuum plasma spray (VPS) is the aerospace gold standard: near-wrought density (<1% porosity), oxide-free splats, best creep and oxidation performance — and the highest cost. Pick HVOF for standalone corrosion overlays and dense bond coats. Pick APS for TBC bond coats where roughness is a feature. Pick LPPS/VPS when a flight-critical hot section needs the cleanest possible deposit.

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.

Oerlikon Metco — Amdry 962 NiCrAlY Thermal Spray Powder
“Amdry 962 (Ni-22Cr-10Al-1Y) coatings are used as bond coats for ceramic top coats or by themselves to resist corrosion at temperatures up to 980°C (1800°F) if applied using atmospheric plasma spray, or up to 1050°C (1920°F) if applied using HVOF or controlled atmosphere plasma spray. The chromium and aluminum provide protection through formation of an oxide scale; the addition of yttrium acts to improve the adhesion of this oxide layer.”
Höganäs — AMPERIT 415 / 410-series MCrAlY Thermal Spray Powders
“AMPERIT 410-series NiCoCrAlY/NiCrAlY powders (particle size 45/22 µm) are suitable for APS, HVOF, and VPS (LPPS) deposition, stable at high temperatures in hot corrosive or oxidizing environments; applied on turbine blades and as bond coats under ceramic top coats.”
Frontiers in Materials — Mechanical, Tribological, and Oxidation Resistance Properties of NiCrAlY Coating by Atmospheric Plasma Spraying (2019, peer-reviewed)
“APS NiCrAlY coating hardness 329.8 ± 16.9 HV as-sprayed, rising to 371.1 ± 19.6 HV after 1100°C heat treatment; peak bond strength 62.1 MPa and porosity 3.06% after 1100°C heat treatment. MCrAlY coatings protect hot parts of rotary and static blades in gas turbines and aircraft engines.”
A Study on Long-Term Oxidation and Thermal Shock Performance of Nanostructured YSZ/NiCrAlY TBC with a Less Dense Bond Coat (PMC / NIH, peer-reviewed)
“NiCrAlY bond coat (AMPERIT 413, particle size 5-45 µm) under YSZ withstood 800h at 1150°C without major exfoliation; thermal-shock testing achieved 1242 cycles at 1200°C and 555 cycles at 1250°C before 30% spallation. TGO grows from 0% to 51.84% of the bond-coat volume over 800h.”
Journal of Materials Science — Research progress on the high-temperature oxidation resistance and hot corrosion resistance of MCrAlY coatings (2025, peer-reviewed review)
“MCrAlY alloy coatings are extensively utilized as bond coats in thermal barrier coating systems due to their excellent high-temperature properties; the MCrAlY bond coat protects the substrate from corrosion and oxidation by forming a protective thermally grown oxide (TGO) layer on its surface.”
DOE NETL Gas Turbine Handbook 4.4.2 — Protective Coatings for Gas Turbines
“MCrAlY overlay coatings (M = Ni, Co, or NiCo) are the industry standard for hot-section oxidation and hot-corrosion protection on gas-turbine blades and vanes, applied as bond coats beneath YSZ thermal barrier coatings or as standalone overlays on land-based turbines.”
European Turbine Network — A Practical Guide for Thermal Barrier Coatings in Gas Turbines
“Conventional TBCs consist of an MCrAlY bond coat for oxidation resistance (typical thickness 100-300 µm) and a YSZ ceramic top coat for thermal insulation; bond coat is deposited by HVOF, APS, or VPS/LPPS depending on oxidation-life and porosity requirements.”
NASA NTRS — Performance of Two-Layer Thermal Barrier Systems on Turbine Blades (NASA Lewis / Glenn)
“NASA flight-rig evaluation of two-layer NiCrAlY bond coat + YSZ top coat on turbine blades established the architecture as the baseline for flight-qualified TBC systems; scale adherence attributed to yttrium reactive-element effect on alumina TGO.”
Journal of Thermal Spray Technology — Microstructure and Properties of HVOF-Sprayed NiCrAlY Coatings (peer-reviewed)
“HVOF-sprayed NiCrAlY coatings exhibit microhardness of 486 HV, tensile bond strength of 54 MPa, and porosity of 1.56 vol% — significantly denser than APS deposits (5.63% porosity) and with 40% higher bond strength.”
Corrosion Science — YSZ/NiCrAlY interface oxidation of APS thermal barrier coatings (peer-reviewed)
“The TGO formed at the YSZ/NiCrAlY interface evolves from a bi-layered α-Al₂O₃ structure through Y₃Al₅O₁₂ (YAG), NiCr₂O₄, and NiO phases; alumina scale thickness at spallation is the governing failure criterion for TBC life.”

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.

MCrAlY (Nickel-base)

Technical data

Where it earns its keep

Where it doesn't

Typical applications

Wear modes addressed

Industries

Substrates

Which process, when?

Sources

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