Answer
A-286 is an iron-base superalloy designed for high-strength applications at temperatures up to $1300^\circ F$. Unlike carbon steels that lose all structural integrity above $400^\circ F$, A-286 maintains a high yield strength and oxidation resistance. In jet engines, wave springs are used to maintain axial tension on bearings or seals. The heat treatment involves a solution anneal followed by precipitation hardening at $1325^\circ F$. The resulting microstructure contains $Ni_3Ti$ precipitates which block dislocation movement. When designing with A-286, engineers must use a reduced Modulus of Elasticity ($E \approx 23 \times 10^6$ PSI at $1000^\circ F$) in their rate calculations to ensure the required preload is achieved at operating temperatures.
