Accurate Measurements of Wettability of Molten Aluminum on Alumina Surface at High Temperature
The wettability of molten materials at high temperatures plays a crucial role in the improvement of welding process.Good wettability not only improves weld quality and reduces welding defects but also contributes to lowering manufacturing costs and increasing production efficiency.A low-cost experimental platform composed of tube furnace,camera,light source,vacuum pump and computer was built,and the wettability experiments of the molten Al on Al2O3 substrates under various temperature conditions in a vacuum environment were conducted employing the sessile drop and pendant drop methods,and high quality images with clear edge contours and noticeable contrast were obtained.Using the developed wettability parameter measurement procedure,the contact angle,surface tension,coefficient of thermal expansion and spreading velocity were calculated.The results show that the measurement of wettability parameters has high accuracy,and the temperature increase can promote the wetting of molten Al on Al2O3 substrate,which is manifested by obvious decrease of contact angle and obvious increase of spreading radius.
aluminum meltsaluminawettabilitysessile drop methodpendant drop methodimage processing
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