Structure and morphology studies of chromium film at elevated temperature in hypersonic environment

• Published in: Bulletin of materials science Vol. 35; no. 3; pp. 341 - 345
• Main Authors: HEGDE, G M, KULKARNI, V, NAGABOOPATHY, M, REDDY, K P J
• Format: Journal Article
• Language: English
• Published: India Springer-Verlag 01.06.2012; Springer Nature B.V
• Subjects: Ablation; Chemistry and Materials Science; Chromium; Chromium oxides; Drag reduction; Engineering; High temperature; Hypersonic flow; Materials Science; Mathematical models; Morphology; Phase composition; Phases; Photomicrographs; Scanning electron microscopy; Shock heating; Sublimation; Surface reactions; drag reduction; surface morphology; Cr coating; Cr oxidation
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/s12034-012-0287-5

This paper presents the after shock heated structural and morphological studies of chromium film coated on hypersonic test model as a passive drag reduction element. The structural changes and the composition of phases of chromium due to shock heating (2850 K) are characterized using X-ray diffraction studies. Surface morphology changes of chromium coating have been studied using scanning electron microscopy (SEM) before and after shock heating. Significant amount of chromium ablation and sublimation from the model surface is noticed from SEM micrographs. Traces of randomly oriented chromium oxides formed along the coated surface confirm surface reaction of chromium with oxygen present behind the shock. Large traces of amorphous chromium oxide phases are also observed.