An Investigation of Very-High-Speed-Drop-Impingement Erosion of 1100 Aluminum
Abstract
An investigation of five available specimens of 1100-0 aluminum, which were tested under waterdrop impingement at velocities from Mach 1.5 to Mach 4, was undertaken to determine the mechanism of erosion of aluminum at very high velocities. The results of inspection of the eroded specimens with use of a light microscope and scanning electron microscope revealed that plastic flow of the aluminum increased as the test velocity increased. Cross-sectional cuts of the specimens revealed a small smount of work-hardening at velocities of Mach 2.5 and above, but no evidence of crack formation was found. These findings are compatible if the heat generated by the amount of plastic flow of aluminum that occurs is large enough to anneal the worked metal. If this is the case, aluminum is a permanently plastic material. Two mechanisms of metal removal are considered. The first, which is applicable at velocities up to Mach 2.5, is the breaking off of proturberances formed by plastic flow of the metal. The second, which is applicable at velocities above Mach 2.5, is the extrusion of separate masses of metal which have become surrounded by surfaces of discontinuity as a result of the pummeling effect of the individual waterdrop blows. The second mechanism of metal loss can be expected to progress as a layer-removal process.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1971
- Accession Number
- AD0728654
Entities
People
- Olive G. Engel
Organizations
- University of Dayton