Visual inspection of castings

I have been involved in the visual inspection of various products,

There are difficult types of products.

For example, "dents" in castings or "caves" are difficult,

We have not found the best answer.

This is because the surface of cast skin is uneven and does not have a consistent pattern.

The photo above shows a "gentle strike" on one of the castings.

Lighting from various directions,

Finally, something that looks like a strike can be seen.

(Slightly lower right of center section)

However, because the surface irregularities turn white or black.

A simple method of registering good products would result in a wide range of good products.

THEN, THE DENTS THAT WE WANT TO MAKE THIS NG WOULD BE IN THE RANGE OF GOOD PRODUCTS,

detection is no longer possible.

In order to detect these dents and burrows in a stable manner,

It is necessary to illuminate the light from various directions and inspect it.

Another method is to erase fine irregularities, as in the case of a smoothing filter.

HOWEVER, IT IS DIFFICULT BECAUSE THE DENTS THEMSELVES THAT WE WANT TO NG MAY DISAPPEAR WITH THAT PROCESS.