Contact Us

Shenzhen Runpeng Precision Hardware Co.,Ltd

The contact:Susan Liao

Mobile:86-18925258235

Phone:86-755-29886925 

Fax:86-755-29886926

E-mail:sales@szrunpeng.cn

Web:www.sz-runpeng.com

Add:Building 69-70, 4th Industrial Zone, Mashantou, Gongming Town,Shenzhen,China.


News
Home > News > Content

Die Casting Shrinkage And Shrinkage Defects

  die casting shrinkage and shrinkage defects

  Both shrinkage and shrinkage are common die casting defects in die casting production. Shrinkage is the die casting in the condensation process in the condensation, can not get the metal solution to add the holes, irregular shape, hole wall rough, generally located in the hot section of the die casting. Shrink holes and stomata are often very similar in appearance, often easily confused. In general, the inner wall of the pores is smooth, and the inner wall of the pores is the distal shape of the dendritic crystals. Shrinkage is the final solidification of the die casting area without the addition of metal solution to form a dispersed and small holes, often appear in the thick section of the die casting and the thickness of the cross-section junction or hot nodes. Loose loose distribution area is much larger than the shrinkage, often hidden in the die casting of the internal, sometimes not notice the naked eye. Shrinkage and shrinkage in the die casting waste occupies a large proportion, must be given enough attention to improve the die casting pass rate.

  I combined with years of experience in production practice, talk about the die casting shrinkage and shrinkage of the causes and preventive measures.

  1. die casting and design

  (1) die casting cross-sectional size change is too large. If the size of the die castings in the design changes too large, the cooling rate of the thin section is much faster than the condensation rate of the adjacent thick sections, which makes it difficult to solidify the die castings at the same time. Design to try to avoid this situation, or should be used cold iron, in order to achieve the order of solidification of the die casting and conducive to fill.

  (2) die casting section is too thick, if not take the appropriate measures to fill it, due to poor formation of shrinkage shrinkage.

  (3) fillet is too small. die casting corner angle radius is too small, will lead to reduced heat transfer capacity of the sand, solidification rate decreased, while the sand because of the strong heat, gas pressure, precipitation of gas can not penetrate into the molten metal, resulting in die casting Air shrinkage.

  (4) rounded too large. Fillet is too large, then the fillet part becomes a thick section, if the adjacent section is thin, it is difficult to get effective filling, resulting in poor filling

  2. looks like

  (1) mold or core box wear caused by thinning of the die casting, resulting in thinning of the die casting section thickness and hinder the shrinkage.

  (2) improper appearance or appearance of improper appearance, resulting in the die casting section is too thick or too thin. Design should pay attention to control the thickness of the appearance, as far as possible to the adjacent thick section of the thin section to maintain the maximum thickness.

  Sand box

  (1) the upper box is too shallow. Production in order to save the amount of sand or in order to reduce the cost of sand boxes and modeling the use of high enough on the box, which is caused by loose loose defects common causes. The upper case is too shallow to reduce the static pressure of the molten metal, so that it is difficult to make up, the pressure is not enough, will lead to shrinkage or shrinkage, or both. If you have to use the case of shallow on the box, you should use the riser or gate cup to make up for the problem caused by too shallow on the box, you can also use the heating riser or constantly add riser to the metal To improve the efficiency of filling.

  (2) The flask is too small. In order to save sand, reduce costs, and sometimes use the size of the sand box shape. The size of the flask is too small to affect the proper placement of the pouring system or to cause the riser to be too close to the wall of the flask. The molten metal in the riser is prematurely cooled and solidified before the filling is completed. You can try to use the heating riser and rain gate to solve these problems.

  (3) the box is not suitable. Due to the size of the box does not match, can not be a good support sand, resulting in displacement or deformation of the wall, forming a thick section of the die casting, so that the original design of the riser is not enough to fill it.


Feedback
This is Shenzhen Runpeng Precision Hardware Co.,Ltd, If you have any questions, requests, etc., please feel free to use this form to contact us. All your comments and suggestions are welcome.
Contact us

Shenzhen Runpeng Precision Hardware Co.,Ltd

The contact:Susan Liao

Mobile:86-18925258235

Phone:86-755-29886925 

Fax:86-755-29886926

E-mail:sales@szrunpeng.cn

Web:www.sz-runpeng.com

Add:Building 69-70, 4th Industrial Zone, Mashantou, Gongming Town,Shenzhen,China.


Copyright ©Shenzhen Runpeng Precision Hardware Co.,Ltd All rights reserved.