如何避免压铸产品（压铸件）上的气孔问题？

压铸件（压铸产品）上的缺陷： 6.气孔，

气孔问题描述：

气孔是由压铸产品中卷入的空气造成的。气孔从压铸产品的外表面不可见，产品的外表面光滑，内部呈现规则的圆形或椭圆形形状。

造成气孔的原因：主要是因为压铸生产过程中卷入了空气

1、内浇口位置的选择不合理，导致不适当的流动方向，当金属液体压射进压铸模具的型腔时，造成正面撞击而形成涡流。

2、浇口的形状设计不合理

3、压射室的金属液体容量太低

4、金属液体在内浇口处的速度过高，造成涡流现象

5、排气不足

6、深腔产品

7、生产过程中喷过多的脱模剂，在金属液体填充进压铸模具之前，没有挥发完全

8、金属锭不干净，提炼不干净

9、加工余量过大

压铸产品（压铸件）气孔问题的解决方法

1、内浇口位置和金属液体在压铸模具中流动方向的选择，以有利于压铸模具中型腔气体的排除为原则。避免金属液体首先堵住排气系统。

2、流道浇口尽可能设置在压铸产品截面积较大的部位

3、增加压射室的金属合金填充量，尽可能使用较小的压射室，定量压铸

4、为了满足成型条件，加大内浇口的厚度，降低充填速度

5、在压铸产品的末端，开渣包和排气，避免渣包和排气过早被金属液体封死

6、深腔产品，在排期的末端，设计镶件增加排气

7、脱模剂用量要少，要尽可能均匀，在充填时挥发完全

8、金属锭块必须完全干净和干燥，并且严格按照熔料流程操作

9、在慢射速和快射速的转换点，调整压射速度

10、降低浇铸的温度和增加一定的压力

How to eliminate stoma in die casting parts?

Defects in die castings: 6. stoma

Other name: air hole, air, gas porosity, blow holes

Characteristic: the gas formed by the gas in the die-casting part has regular shape and relatively smooth surface.

Causes：The main cause is the inclusion of gas,

1、the choice of gate location and improper flow guide, resulting in metal liquid into the cavity, resulting in a positive impact and vortex.

2、sprue shape design is not good.

3、the pressure chamber is not full enough.

4、the gate speed is too high, resulting in turbulence.

5、poor ventilation.、

6、mold cavity location is too deep.

7、too much paint, not burned before filling.

8、the burden is not clean, poor refining.

9、machining allowance is too big.

elimination measures

1、the gate position and the flow guiding shape which are favorable to the cavity gas exclusion are selected to prevent the metal liquid from blocking the discharge system on the parting surface first. Cross sectional area of the nozzle

2、sprue gate should be possible within the large cross-sectional area.

3、increase the pressure chamber fullness, as much as possible the use of smaller pressure chamber, and quantitative casting.

4、in order to meet the molding conditions, increase the gate thickness to reduce the filling speed.

5、in the last part of the cavity filled open the overflow tank and exhaust, and should avoid overflow and exhaust by liquid metal seal.

6、deep cavity at the vent plug, use the mosaic form to increase the exhaust.

7、paint dosage is thin and even, burn out after filling, use the small amount of paint.

8、the burden must be handled clean and dry, strictly abide by the smelting process.

9、Adjust the injection speed, the transition point of the slow injection velocity and the fast injection velocity.

10、reduce pouring temperature and increase specific pressure.