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一、前言表示铸型透气性的程度,分为湿态干态及高温透气率。通常,只把湿态透气率称作透气率,表示气体通过多孔介质时透过能力的数值,是与空隙率、颗粒形状和大小有关的常数。近年来也有人认为,透气率只不过是用不同形式表现了铸型的填充密度,干态透气率也是如此。实际上,当诸型内浇注金属液时,铸型处于高温状态,而通过铸型的气体温度也被升高,根据这种观点,也可采用使空气通过高温试样求
First, the foreword indicates the degree of mold permeability, divided into wet dry state and high temperature air permeability. In general, the wet air permeability is simply referred to as air permeability, which is a numerical value of gas permeability when passing through a porous medium and is a constant related to the porosity, particle shape and size. In recent years, some people think that the air permeability is only expressed in different forms of filling density of the mold, dry air permeability as well. In fact, when the molten metal is poured into the molds, the mold is at a high temperature and the temperature of the gas passing through the mold is also increased. From this point of view,