AMS 5892
AMS 5892 covers Incoloy 909 (UNS N19909) controlled-thermal-expansion nickel-iron-cobalt alloy in sheet and strip form — the thin-section product for formed engine sealing elements, structural sheet metal, and precision components in gas turbine engines requiring the matched low thermal expansion coefficient of the 909 alloy. Sheet and strip material from AMS 5892 is used for formed knife-edge seal rings, thin-section structural members, and sheet metal fabrications in engine hot sections where the CTE of the Incoloy 909 must match a ceramic, titanium, or composite mating structure across the 70–1200°F operating temperature range.
The 909 alloy achieves its controlled CTE through the specific Ni-Fe-Co balance that suppresses the standard Ni-Fe Invar effect to a precisely predictable low value, combined with precipitation hardening that develops 130 ksi yield — providing structural capability alongside the dimensional stability requirement. AMS 5892 is the sheet form companion to AMS 5884 bar and AMS 5893 plate for complete coverage of Incoloy 909 product forms.
Mechanical Properties (AMS 5892 — Incoloy 909 Sheet, Solution-Treated)
- Minimum Tensile Strength (solution-treated): 100,000 psi (689 MPa)
- Minimum Yield Strength (0.2%): 50,000 psi (345 MPa) — solution-treated, before aging
- After Age Hardening: Min yield 130,000 psi, Min UTS 155,000 psi
- Minimum Elongation (solution-treated): 30%
- CTE (70–1200°F): ≈ 7.7 × 10⁻⁶/°F
- Sheet thickness: 0.004 inch to 0.187 inch
AMS 5892 sheet is supplied in the solution-treated condition (1800°F, water quench) for forming operations. Forming is performed in the solution-treated condition where ductility is maximum. After forming, the sheet assembly or component is age-hardened: 1400°F/8 hours, air cool + 1200°F/8 hours, air cool — simultaneously developing properties and locking in the final formed geometry. The aging process introduces limited distortion from precipitation volume change; fixture aging with controlled jigging is standard for precision sealing ring components.
- Formed gas turbine engine thin-section sealing elements and diaphragms
- Engine hot-section sheet metal structural fabrications requiring CTE match
- Thin-wall structural components in gas turbine cases and flanges
- Formed aerospace instrumentation housings requiring dimensional stability across temperature
- Gas turbine engine transition duct sheet metal in low-CTE stainless-alternative
- Precision sheet metal components in engines where differential thermal expansion is critical
AMS 5884 — Incoloy 909 Bar
Incoloy 909 bar and billet — the machined bar form for sealing rings and precision components in the same controlled-CTE alloy.
AMS 5893 — Incoloy 909 Plate
Incoloy 909 plate — the thick-section product form for machined structural components and flanges in 909 CTE alloy.
Certified Material for Critical Service
AMS 5892 mill test reports document Incoloy 909 chemistry, solution-treated condition, and mechanical properties in the solution-treated condition (properties after aging are typically verified by the component manufacturer). Sheet and strip dimensions (thickness, width, flatness, camber) are per AMS 5892 tolerance tables. For bar and billet see AMS 5884; for plate see AMS 5893. All three specifications cover the same 909 composition in different product forms.