EVALUATION OF CAVITATION-CORROSION RESISTANCE AND RECIPROCATING WEAR RESISTANCE OF SURFACE COATED AND CRYOGENICALLY TREATED SILICON BRASS

Open Access
- Author:
- Simmons, Nathan Daniel
- Graduate Program:
- Engineering Mechanics
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- April 08, 2008
- Committee Members:
- Albert Eliot Segall, Thesis Advisor/Co-Advisor
- Keywords:
- Surface Treatment
Cryogenic
Dezincification
Corrosion
Cavition - Abstract:
- Cavitation and corrosion resistance are important characteristics to consider in marine environments with flowing liquid. Impellers and propellers are used in many applications and are exposed to erosion due to the mechanisms of corrosion and cavitation, which leads to their failure and replacement. Considerable work has been done to produce surface coating treatments that resist cavitation and corrosion, but little work has been done to treat the entire material throughout. Surface coating and cryogenic treatment combinations of silicon brass were analyzed in this study due to the potential for increased erosion resistance using a relatively cheap treatment. The cavitation environment was provided by an ultrasonic cavitation apparatus in two different corrosive mediums, tap and Artificial Seawater. The samples to be tested and analyzed were coated with one of four paint pens, cryogenically treated, and tested. During testing it was noticed that the coating was not adhering well to the substrate and additional efforts had to be taken to assist the coating adhere better. To help the coating adhere better, some samples were oxidized or sandblasted. A set of samples tested in artificial seawater had the coating removed prior to testing because it was determined that through testing the poorly adhering coating contributed significantly to the samples mass loss. The samples tested with the coating intact did not perform as well as the samples that had the coating removed prior to testing that exhibited a mass loss roughly 10 fold less than the baseline material. In addition to the cavitation and corrosion resistance tests, reciprocating wear tests were also conducted on samples subjected to the same treatments above to determine if the treatment could be used to reduce mass loss due to reciprocating wear. Results indicate that the treatment method did not decrease the mass loss of reciprocating wear samples.