| Wetting and spreading of liquid systems on solid substrates under transient conditions, driven by surface tension and viscous forces along with the interface interactions (e.g., a substrate dissolution or diffusion and/or chemical reaction) is a complex problem, still waiting to be fully understood. In this study we have performed an extensive experimental investigation of liquid aluminum alloy spreading over aluminum substrate along with corroboration with theoretical modeling, performed in separate but coordinate study. Wetting and spreading to be considered take place during a transient formation of the free liquid surface in both sessile drop and wedge-tee mating surfaces' configurations. The AA3003 is used as a substrate and a novel self-fluxing material called Trillium(TM) is considered as the filler metal. In addition, benchmark, non-reactive cases of spreading of water and silicon oil over quartz glass are considered. The study is performed experimentally by a high temperature optical dynamic contact angle measuring system and a standard and high speed visible light camera, as well as with infra read imaging. Benchmark tests of non-reactive systems are conducted under ambient environment's conditions. Molten metal experiment series featured aluminum and silicone alloys under controlled atmosphere at elevated temperatures. The chamber atmosphere is maintained by the ultra-high purity nitrogen gas purge process with the temperature monitored in real time in situ. Different configurations of the wedge-tee joints are designed to explore different parameters impacting the kinetics of the triple line movement process. Different power law relationships are identified, supporting subsequent theoretical analysis and simulation. Under ambient temperature conditions, the non-reactive liquid wetting and spreading experiments (water and oil systems) were studied to verify the equilibrium triple line location relationships. The kinetics relationship between the dynamic contact angle and the triple line location is identified. Additional simulation and theoretical analysis of the triple line movement is conducted using the commercial computer software platform Comsol in a collaboration with a team from Washington State University within the NSF sponsored Grant ;Keywords: Kinetics, Wetting and Spreading, Wedge-tee, Trillium(TM), Model. |
