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一、铝合金的除气处理铝合金在液态时对氢有强大的溶解特性,其溶氢量占溶解气体总量的80%左右;且当其在沸点以下时,对氢气的熔解是随温度升高而呈直线增加的,在降温过程中因过饱和而析出的氢,在液态由于受铝液表面张力、致密的表面氧化膜、合金的粘度以及非金属夹杂物对氢的吸附干扰因素的影响;在合金凝固时又因遇到金属结晶的阻碍而不能外逸时,就会停留在结晶间,形成铸件的针孔。
First, the aluminum outgassing process Aluminum alloy in liquid hydrogen has a strong dissolving properties, the amount of dissolved hydrogen accounted for about 80% of the total dissolved gas; and when it is below the boiling point, the hydrogen is melted with temperature Increased by a linear increase in the cooling process due to supersaturation and precipitation of hydrogen in the liquid due to the liquid aluminum surface tension, dense surface oxide film, the viscosity of the alloy and non-metallic inclusions interference hydrogen adsorption factors Influence; in the solidification of the alloy because of the metal crystallization of the obstacles and can not escape, it will stay in the crystallization, the formation of the pinhole.