低压铸造和重力铸造

低压铸造和重力铸造

Low pressure casting and high pressure casting

低压铸造是液体金属在压力作用下充填型腔，以形成铸件的一种方法。由于所用的压力较低，所以叫做低压铸造。其工艺过程是：在密封的坩埚（或密封罐）中，通入干燥的压缩空气，金属液在气体压力的作用下，沿升液管上升，通过浇口平稳地进入型腔，并保持坩埚内液面上的气体压力，一直到铸件完全凝固为止。然后解除液面上的气体压力，使开液管中未凝固的金属液流坩埚，再由气缸开型并推出铸件。

Low pressure casting is a method of molten metal fills the cavity u nder the pressure and then forms the casting .due to the pressure i s not high ,so it is called low pressure casting .The technical pro cess is : in the hermetic crucible (or sealed pot ) injecting the dry compressed air ,molten metal under the effect of gas pressure go es up along the pipe then through the gate placidly run into the c avity ,then keep the gas pressure upper the liquid in the crucible until the casting solidification totally .then remove the gas pressure to make the unfreezing metal in the pipe for opening run back into the crucible and at the same time use the cylinder open cavi ty to detrusion the casting .

低压铸造独特的优点表现在以下几个方面：

The unique characteristics of low pressure casting performed as below :

1．液体金属充型比较平稳；Molten metal full the cavity smoothly.

2．铸件成形性好，有利于形成轮廓清晰、表面光洁的铸件，对于大型薄壁铸件的成形更为有利；

The forming property is good and in favor of forming the edge shape ness and surface bright and clean .It is favorable for the large ca sting parts with thin section casting

3．铸件组织致密，机械性能高；

The tissue of casting is densification ,and mechanical behavior is hi gh .

4．提高了金属液的工艺收得率，一般情况下不需要冒口，使金属液的收得率大大提高，收得率一般可达90％。

低压铸造独特的优点表现在以下几个方面：

The unique characteristics of low pressure casting performed as below :

1．液体金属充型比较平稳；Molten metal full the cavity smoothly.

2．铸件成形性好，有利于形成轮廓清晰、表面光洁的铸件，对于大型薄壁铸件的成形更为有利；

The forming property is good and in favor of forming the edge shape

ness and surface bright and clean .It is favorable for the large ca sting parts with thin section casting

3．铸件组织致密，机械性能高；

The tissue of casting is densification ,and mechanical behavior is hi gh .

4．提高了金属液的工艺收得率，一般情况下不需要冒口，使金属液的收得率大大提高，收得率一般可达90％。

低压铸造独特的优点表现在以下几个方面：

The unique characteristics of low pressure casting performed as below :

1．液体金属充型比较平稳；Molten metal full the cavity smoothly.

2．铸件成形性好，有利于形成轮廓清晰、表面光洁的铸件，对于大型薄壁铸件的成形更为有利；

The forming property is good and in favor of forming the edge shape ness and surface bright and clean .It is favorable for the large ca sting parts with thin section casting

3．铸件组织致密，机械性能高；

The tissue of casting is densification ,and mechanical behavior is hi gh .

4．提高了金属液的工艺收得率，一般情况下不需要冒口，使金属液的收得率大大提高，收得率一般可达90％。

Improve the yield rate of the molten metal,normally don’t need the dead head,and make the yield rate a high improvement,usually can achieve 90%.

此外，劳动条件好；设备简单，易实现机械化和自动化，也是低压铸造的突出优点。

in addition ,working condition is good ,equipments is not complicated and easy to realise mechanization and automation are also the hig hlight advantage .

重力铸造是指金属液在地球重力作用下注入铸型的工艺，也称浇铸。广义的重力铸造包括砂型浇铸、金属型浇铸、熔模铸造、消失模铸造，泥模铸造等；窄义的重力铸造专指金属型浇铸。

Gravity casting is that molten metal run in to the mould with the pressure of earth gravity ,it is also named pouring casting, generali zed pouring casting incl. Sand casting ,metal mould casting ,investmen t casting ,evanescent mold casting and mud die casting ,ect. Narrowly pouring casting is the metal mould casting .

把金属材料做成所需制品的工艺方法很多，如铸造、锻造、挤压、轧制、拉延、冲压、切削、粉末冶金等等。其中，铸造是最基本、最常用的工艺。