Ensuring the quality of the casted components is critical in the process of die casting. This is done mostly in the post casting stages, where the components are subjected to different examination procedures. This will help in identifying the defects in the casted components and apply the necessary fixes before shipping them off to the respective clients. The castings that emerge first are subjected to rigorous inspections that focus on its dimension and patterns. Some of the inspection methods used for identifying defects in castings are described below.
Ultrasonic inspection can detect any sort of cracks or other abnormalities within the casting, with a very high accuracy. Most die cast companies used ultrasonic testing to check the quality of the casted components. In this process, an ultrasonic signal is sent through the casting and the return signal monitored to find errors in the casting.
If the casting has any defect in its interior, it can change the wavelength of signal that is reflected back to the detector thereby helping to identify any defects. Moreover, the time interval between the transmitted and received signal can help to ascertain the exact location of the defect inside the casting.
Radiographic examination is another inspection method used to identify defects in a casting. This method is expensive as it needs the proper equipment and only some die casting companies use it. A radiographic examination involves the use of both X-rays and γ-rays for detecting any sort of defects in the casting.
A film placed behind the casting can register the flow of rays through the casting in the form of variations in exposure that will help to identify any defects. An advantage of radiographic examination is that it can detect most of the defects such as cracks, void, tears, nonmetallic inclusions and porosity in the castings.
Carrying out a detailed visual inspection is the most commonly used method to identify any defects in castings. A visual inspection can reveal some of the commonly occurring defects on casted components such as surface cracks, roughness, missing cores, and shifts. Special instruments such as an articulating fiberscope are used to carry out detail examinations of the surface of the castings. Moreover, other method like hitting the cast with a mallet and checking the tone is also used to identify any cracks in the casting surface.