How to avoid shrinkage holes and shrinkage problems on die castings

I. Characteristics and inspection methods:

(1) Anatomical or flaw inspection, the shape of the holes is irregular, unsmooth, and the surface is dark-colored.

(2) Large and concentrated for shrinkage holes, small and scattered for shrinkage loose.

II. Causes:

(1) castings in the solidification process, due to the production of shrinkage, do not get the metal compensation, thus causing holes;

(2) Pouring temperature is too high, mold temperature gradient distribution is unreasonable;

(3) Pressure injection ratio pressure is low, the pressurization pressure is too low;

(4) The inner gate is thin, the area is too small, premature solidification, is not conducive to the pressure transfer and the liquid metal complementary contraction;

(5) The casting structure has a hot section parts or cross-section changes drastically;

(6) The amount of liquid metal pouring is small, the residual material is too thin, can not play the role of shrinkage.

III.Treatment methods:

(1) Reduce the casting temperature to minimize shrinkage;

(2) Improve the specific pressure of compression injection and pressurization pressure to improve the densification;

(3) Modify the inner gate, so that the pressure is better transferred, in favor of liquid metal shrinkage effect;

(4) Change the casting structure, eliminate metal accumulation parts, wall thickness as uniform as possible;

(5) Speed up the cooling of thick parts;

(6) Thicken the material handle 15~30mm, increase the effect of contraction.

• 

  EMP Die Casting Company—A Rising Star

  Recently, EMP Die Casting Co., Ltd has become a rising star in China’s die casting industry. Thanks to all the staff’s efforts, we have made great strides in our casting business, reached 37 million...
• 

  The Chinese Die Casting Industry

  In the year 2015, China produced 45.6 million metric tons of castings in total, followed by India (10.8), the US (10.4), Japan (5.4), and Germany (5.3). With 45 % of the total world casting production...
• 

  4 Advantages of Die Cast Aluminum Radiators

  Automobile die-casting aluminum radiator is an indispensable and important component in the automobile engine system, and it is developing in the direction of lightweight, high efficiency, and economy...