Appearance inspection: the surface of the die casting has the convex or concave trace of reticular hair, which is expanded and extended with the increase of the number of die casting.

The reasons are as follows:

1) the surface of the die casting cavity is cracked

2) non-uniform preheating of die casting mold

The solutions and prevention methods are:

1) if the die casting die is to be cast regularly or for a certain number of times, it shall be annealed to eliminate the stress in the mold cavity

2) if a turtle crack has appeared on the surface of the cavity, it shall be polished to form the surface and the crack layer shall be removed

3) mold preheating shall be uniform