采用一种新型定子−转子型强剪切装置，通过水模拟实验和铝熔体除气实验相结合的方法研究强剪切作用对铝合金除气过程中氩气泡的影响规律，进而研究其对7075铝合金的除气作用。结果表明：强剪切对氩气泡具有强烈的破碎和分散作用，能够将通入熔体的气泡转变为非常细小的气泡，并均匀分布于熔体之中。这种强剪切作用对7075铝合金具有非常高效的除气作用。在适当的除气条件下，经过1 min除气，合金密度指数Di由13.20%降低到0.65%，实测铝中氢的含量由2.90μL/g降低到1.10μL/g，这显著优于传统旋转除气方法。还详细研究除气时间以及除气后静置时间对氢含量的影响，并分析强剪切工艺高效除气的机理。%The water simulation and alloy melt degassing experiments were carried out to study the effect of intensive shearing on Ar bubbles and its effect on the degassing of 7075 alloy by the application a newly developed stator-rotor type high shear unit. The results show that the intensive shearing can significantly disperse the Ar bubbles and improve the uniformity of their distribution. The alloy degassing experiments show that the high shearing can evidently degas 7075 aluminium alloy with a high efficiency. Under a proper degassing condition, after degassing for 1 min, the density index decreases from 13.20% to 0.65% and the measured concentration of hydrogen in the melt Al obviously reduces from 2.90μL to 1.10μL, which shows a much higher efficiency than that using the conventional rotary degassing method. The effects of the degassing time and isothermal holding time after degassing on hydrogen content were also studied and the mechanism of high efficient degassing of intensive shearing was analyzed.
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