High-Temperature Single Crystal Preloader

About this technology

Overview

Many aerospace vehicles require thermal barriers/seals to minimize the flow of hot gases through interfaces in thermal protection systems and propulsion systems where temperatures can exceed 1200°F. One of the primary challenges is maintaining proper sealing contact at elevated temperatures. To address this challenge, preloading elements in various spring-like forms are often incorporated into or behind a seal to provide the required resiliency. At these elevated temperatures, conventional spring preloaders made from polycrystalline alloys lose strength and can exhibit excessive creep, resulting in a loss of sealing contact. Glenn innovators have developed new processes to enable the fabrication of preloaders made of single crystal superalloys that can increase the upper limit of thermal seals to greater than 2000°F for short to moderate term applications, and greater than 1800°F for long term applications. These preloaders can be manufactured in a variety of configurations allowing stiffness to be customized for a particular application.