X - ray examination of the Internal defects of die casting

Sieg-Huao is an experienced supplier of high pressure die casting for more than 30 years in Nanjing, China. Our products mainly include aluminum die casting parts and zinc alloy die casting parts. To ensure qualified aluminum die casting products we have applied X-ray examination of internal defects.

Die Casting is one of the basic processes of modern machinery manufacturing industries, with the advantages of low cost, primary forming and the manufacturing of large and complex structures. It is widely used in many industrial fields such as automobile parts, machinery manufacturing, electronics, medical instruments, clock instruments, hardware products, aerospace and so on.

As an important basic industry of machinery industry, the improvement of production and processing efficiency and production quality of die casting at the present time with the rapid development of information will be a subject that must be faced by the vast number of casting workers. The high reject rate of casting blank is a common problem in the industry. How to better control the quality of die casting and improve the die casting process is particularly important.

There are many factors affecting die casting quality due to the complexity of die casting process. Loose control of raw materials, unreasonable process scheme, unreasonable design of mold structure and improper production operation will lead to various defects in the casting, including inclusions, air bubbles/pores, loose and cracks.

Common defect 1: crack

It is mainly caused by unreasonable structure design and production process not up to standard. There are two types of cracks: casting crack and heat treatment crack.

The crack is a light color line in the X-ray image.

Common defect 2: air bubbles/pores

The main reason is that the casting is not ventilated during the casting process and it is mixed with air or impurities. Bubbles/pores on workpiece surface can be found by sandblasting, and bubbles/pores inside workpiece can be detected by X-ray fluoroscopy.

Common defect 3: loose

It is mainly caused by unreasonable design structure. Loose casting generally produces the thick and thin transition of the wall near the inner runner, the thick part of the root of the flying riser and the thin wall with large plane.

The defect can be found by X-ray examination. In X-ray images, the defect is seriously filamentous, and generally appears light cloud.

Common defect 4: inclusion

It is mainly caused by dirty furnace materials or improper operation. It is mostly distributed on the upper surface of aluminum castings and at the Angle of non-ventilated casting.

The defect can be found by X-ray examination, which shows dark bulk in X-ray images.

In order to guarantee casting quality and save cost, it is necessary to detect defects in the early stage of production process. X-ray nondestructive testing (NDT) is the preferred method for casting defect detection because it can avoid material waste and improve production efficiency.