Glossary

What are transonic airfoils, and what is the active clearance control? Check out our technical dictionary and find out more about engine technology terms – from active clearance control to velocity triangle.

HAE "Hell" "Hard" anodizing Hard chrome-plating Hardening and tempering Hardfacing Heat exchanger High-pressure compressor High-pressure turbine High-speed milling High-temperature vacuum brazing Hot isostatic pressing (HIP) Hypersonic aircraft

Hardening and tempering

(at 500 - 600°C or 850 - 1050°C)
Hardening and tempering serve as the final heat treatment of nearly finished components to increase their hardness while at the same time obtaining a favorable toughness.
The components are first hardened by rapid cooling, then the desired toughness is produced by subsequent tempering which reduces the hardness to an acceptable level. To avoid oxidation tempering is performed in vacuum or a protective-gas atmosphere. Special fixturing is used to prevent distortion of the components.