铝铸件在进行制作的过程中，其铝合金在熔炼和浇注时，在一定程度上能够吸收大量的氢气，冷却的时候会因为溶解度的下降而不断的析出，铝合金中溶解的较多的氢，其溶解度随合金液温度的升高而增大，随温度的下降而减少，由液态转变成固态时，氢在铝合金中的溶解度下降19倍。
铝铸件的铝合金液在冷却的凝固过程中，其氢的某一时刻，氢的含量超过了其溶解度即以气泡的形式析出。因过饱和的氢析出而形成的氢气泡，来不及上浮排出的，就在凝固过程中形成细小、分散的气孔，即平常我们所说的针孔。在氢气泡形成前达到的过饱和度是氢气泡形核的数目的函数，而氧化物和其他夹杂物则在起气泡核心的作用。
铝铸件在一般生产条件下，特别是在厚大的砂型铸件中很难避免针孔的产生。在相对湿度大的气氛中溶炼和浇注铝合金，铸件中的针孔尤其严重。这就是我们在生产中常常有人纳闷干燥的季节总比多雨潮湿的时节铝合金铸件针孔缺陷少些的原因。一般说来，对铝合金而言，如果结晶温度范围较大，则产生网状针孔的机率也就大得多。这是因为在一般铸造生产条件下，压铸铝件具有宽的凝固温度范围，使铝合金容易形成发达的树枝状结晶。
铝铸件在生产的过程中，其模具是开展工艺顺利进行的先决条件，在确保铝铸件质量方面起到了重要的作用，铝铸件的生产工艺特点主要是为了获得高质量的铝铸件，正确选择工艺参数才是决定因素。总之，正确地选择和调整工艺参数和模具设计是铝铸件生产中各种因素的综合反映。
铝铸件在进行设计的过程中要是合理的话，在实际的生产中能够避免很多问题的发生，这样就可以有效的减少其铸件的不合格率，但是相反，如果模具设计不合理，那么生产出来的铝铸造产品质量也不会好。
铝铸件的强度重量金属压铸件相比塑料注射成型等其他铸造方法，可压铸薄壁复杂的铸件，例如当前鋅合金压铸件最小壁厚可达0.3mm；铝合金铸件可达0.5mm；最小铸出孔径为0.7mm；最小螺距为0.75mm。在一样的尺寸的状况下薄壁压铸件强度会更高些，重量更轻。
In the process of making aluminium castings, its aluminium alloy can absorb a large amount of hydrogen to a certain extent during smelting and pouring. When cooling, it will precipitate continuously because of the decrease of solubility. The more hydrogen dissolved in aluminium alloy, its solubility increases with the increase of the temperature of liquid alloy, decreases with the decrease of temperature. When the liquid is transformed into solid state, hydrogen is in aluminium alloy. The solubility decreased 19 times.
During the cooling and solidification process of aluminium alloy liquid, hydrogen content exceeds its solubility at a certain time, that is to say, it precipitates in the form of bubbles. The hydrogen bubbles formed by the precipitation of supersaturated hydrogen can not float up and discharged. In the process of solidification, fine and dispersed pores, which are commonly referred to as pinholes, are formed. The supersaturation before the formation of hydrogen bubbles is a function of the number of hydrogen bubbles nucleating, while oxides and other inclusions act as the core of bubbles.
It is difficult to avoid pinholes in aluminium castings under general production conditions, especially in heavy sand castings. The pinholes in aluminium alloy castings are especially serious when melted and poured in relatively humid atmosphere. This is why we often wonder in production that pinhole defects in aluminium alloy castings are less in dry season than in wet and rainy season. Generally speaking, for aluminium alloys, if the crystallization temperature range is large, the probability of producing network pinholes is much greater. This is because in general casting production conditions, die-casting aluminium castings have a wide range of solidification temperature, which makes it easy for aluminium alloy to form developed dendritic crystals.
In the production process of aluminium castings, the die is the prerequisite for the smooth process, and plays an important role in ensuring the quality of aluminium castings. The production process characteristics of aluminium castings are mainly to obtain high quality aluminium castings, and the correct selection of process parameters is the decisive factor. In short, the correct selection and adjustment of process parameters and die design are the comprehensive reflection of various factors in the production of aluminium castings.
If the design process of aluminium castings is reasonable, many problems can be avoided in actual production, which can effectively reduce the unqualified rate of its castings. On the contrary, if the design of the die is not reasonable, the quality of the aluminium castings produced will not be good.
Compared with other casting methods such as plastic injection moulding, the strength and weight of aluminum castings can be used to cast thin-walled complex castings, such as zinc alloy die castings with minimum wall thickness of 0.3 mm, aluminum alloy castings with 0.5 mm, minimum cast aperture of 0.7 mm and minimum pitch of 0.75 mm. Thin-walled die castings with the same size have higher strength and lighter weight.
