Metallurgical analysis of Sponson bush of an aircraft

Madan, M and Sujata, M and Bhaumik, SK (2011) Metallurgical analysis of Sponson bush of an aircraft. Project Report. National Aerospace Laboratories, Bangalore, India.

Full text not available from this repository.


A Sponson bush belonging to an aircraft was forwarded to this laboratory for metallurgical analysis. It was requested to identify the specification of the material used by OEM. This exercise was taken up for indigenization of the component fabrication. After the necessary laboratory tests, it was found that the Sponson bush supplied by OEM was made of a precipitation hardenable martensite grade stainless steel. The chemical composition of the bush material was found to be similar to steels of specification MSRR6647 or BSEM 548 or CUSTOM 450 (ASTM specification XM-25). Analysis of the raw material (procured from the local vendor) conformed to the above specifications in terms of chemical composition. Microstructural study, however, showed that the raw material contained higher amount of delta ferrite (4-5%) in comparison to that in the Sponson bush (delta ferrite not detectable). Heat treatment schedule to be adopted for achieving the strength level equivalent to that of the Sponson bush was determined through laboratory experiments, which is provided in this report. In summary, the raw material procured from the local vendor can be used as substitute for fabrication of the Sponson bush. However, it must be ascertained that the raw material is of premium aircraft-quality conforming to AMS 2300 0r MAM 2300. The material shall be procured in solution annealed condition and it shall contain not more than 2% delta ferrite in the microstructure.

Item Type: Monograph (Project Report)
Uncontrolled Keywords: Sponson bush;Precipitation hardenable stainless steel; MSRR6647/BSEM 548/CUSTOM 450
Subjects: AERONAUTICS > Aeronautics (General)
CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
Depositing User: Ms. Alphones Mary
Date Deposited: 08 Jul 2011 08:14
Last Modified: 08 Jul 2011 08:14

Actions (login required)

View Item View Item