Solar Atmospheres (Hermitage, Pa.) and Metalex Manufacturing (Cincinnati, Ohio) have teamed up to thermally process landing gear for a military version of the Boeing 737. Key landing-gear components made from 4340 and 4340M, which typically would have been oil quenched, were processed in a vacuum furnace utilizing inert-gas quenching.
After several successful progressions, Solar Atmospheres was able to replicate the exact results of an oil-quenched process while keeping parts bright and clean and limiting distortion to enable close or near-net shapes. This was accomplished by helium quenching at 10-bar pressure with a 300-HP blower motor running in excess of 5,000 RPM. The success of the inherently uniform vacuum thermal technology resulted in a process change of the landing gear after Boeing engineers confirmed the work with a series of mechanical, dynamic and fatigue test results.