Study On The Wettability Of Molten Aluminum On Coated Substrate

In this paper the sessile drop method was used to measure the wetting behavior of the molten aluminum on alumina,graphite,bulk chromium,bulk nickel,chromium coated alumina,nickel coated alumina and chromium coated graphite under the condition of high vacuum.This paper mainly studied the effect of Cr film thickness and Ni film thickness on the wetting behavior of molten aluminum on alumina substrates,and the effect of Cr film thickness on the wetting behavior of molten aluminum on graphite substrates.The microcosmic mechanism of the effect of film on wetting behavior was analyzed.The wetting behaviors of molten Al on bulk chromium and Cr-coated alumina were studied at 700? and 800?.According to the results of the experiment,chromium film deposited on alumina improved the wettability of molten aluminum on alumina obviously.With the increase of chromium film thickness from 260 nm to 1200 nm,the equilibrium contact angle decreases gradually,spreading rate increased.The increase in temperature made a greater improvement.The wetting behavior of molten Al on bulk chromium and Cr-coated graphite were studied at 700?.According to the results,chromium film deposited on graphite improved the wettability of aluminum on graphite significantly.With the increase of chromium film thickness from 170 nm to 900 nm,the equilibrium contact angle decreases gradually,spreading rate increased.Heat treatment can change the wettability of molten aluminum on Cr-coated graphite.The wetting behavior of molten Al on bulk nickel and Ni-coated alumina were studied at 700?.According to the results,nickel film deposited on alumina improved the wettability with aluminum on alumina obviously.With the increase of nickel film thickness from 100 nm to 1000 nm,the equilibrium contact angle decreases gradually,spreading rate increased.These phenomena are related to the effect of coatings on the liquid-solid interface reaction and the wetting triple line configuration.