Melting and Degradation of Nylon-11 Particles during HVOF Combustion Spraying
Numerical predictions and experimental observations have been correlated to improve the qualitative understanding of the degree of thermal degradation occurring during the HVOF spray deposition of Nylon-11. Particle residence time (<1 ms) in the HVOF jet was insufficient for significant decomposition of the Nylon-11 but was sufficient for noticeable discoloration (yellowing) of the particles of a powder with a mean particle size of 30 μm. Experimental observations showed this to be the case even though numerical predictions indicated that the temperature of a 30 μm diameter particle should be considerably higher than the upper degradation limit of Nylon- 11. Initial thermal oxidation of Nylon-11 promotes the formation of carbon-carbon double bonds that strongly absorb in the visible spectrum even at concentrations of parts per million, resulting in discoloration of the Nylon.
M. Ivosevic R. A. Cairncross R. Knight
Department of Materials Science and Engineering Department of Chemical and Biological Engineering Drexel University, Philadelphia, PA, USA
国际会议
北京
英文
2007-05-14（万方平台首次上网日期，不代表论文的发表时间）