Improving the quality of castings by X-ray nondestructive testing technology

Date：2021-12-31 15:40:00Views：895

With the increasingly stringent requirements of society, laws and regulations on environmental protection and energy saving, the quality requirements of aluminum castings have also been improved. Therefore, the inspection of aluminum castings is paid more and more attention by manufacturers. Aluminum castings are widely used in many industries, including automobile industry, instrument industry, agricultural machinery, machine tool industry and so on.

Inspection quality requirements for aluminum castings

For qualified aluminum castings, the non machined surface of the casting shall be smooth and straight, and the casting trace shall be clear. After cleaning, the pouring riser shall be flush with the casting surface. There shall be no crack, cold barrier, blister, air hole, slag hole, shrinkage, slag inclusion and other defects.

Cracks and compression cracks of aluminum components during press riveting. Cracks have occurred during riveting and pressing of aluminum parts assembly (cracking of riveting tox point and cracking of pressing R angle). The potential influencing factors of compression cracking are detected, measured and analyzed. According to the different uses and requirements of aluminum castings, different inspection methods need to be adopted for the inspection of aluminum castings. The main detection methods are as follows:

1. Appearance inspection

The appearance quality of aluminum castings not only affects the subsequent processing technology, the consumption of subsequent processing, but also affects the performance of castings. The surface quality of aluminum castings, including surface defects, dimensional accuracy, surface roughness, etc., can be visually inspected according to the specified standards.

2. Pressure detection

Perform pressure testing on aluminum castings that are not allowed to leak air, water or oil. Apply soapy water on the outer wall of the casting. If there are blisters, soap bubbles will appear. However, the accuracy of this detection remains to be discussed.

3. X-ray testing

For aluminum castings with complex structure, check whether the internal structure meets the design requirements. Sometimes it is necessary to cut the casting. This can damage aluminum castings. Nondestructive testing equipment is used to test X-ray testing equipment. X-ray detection can be used to detect whether there are blisters and pores in aluminum castings with high detection accuracy.

In fact, there is no difference between X-ray and natural light in essence. They all belong to electromagnetic waves, but the energy of X-ray quantum is much greater than that of visible light. It can penetrate objects that can not be penetrated by visible light and have complex physical and chemical interactions with substances. The quality of aluminum castings not only affects the subsequent processing technology, the consumption of subsequent processing, but also affects the performance of castings. Through the X-ray testing equipment, the invisible defects inside the aluminum castings can be accurately inspected without damaging the aluminum castings, and corrected and improved in time, so as to better ensure the quality of aluminum castings and the quality of finished products will be better.