X-Ray testing ranks top in importance of all of the testing that is done on industrial products. X-ray inspection examines the integrity of the product. X-Ray inspection is also commonly known in the industry as radioscopy or fluoroscopy.
An X-ray tube emits x-rays which are directed onto the cast objects and are detected by digital imaging. Any product defects, degradations or cavities such as porosity, are detected by X-Ray inspection.
X-Ray imaging begins by taking a large number of two dimensional (2D) X-ray images. Acquisition can be through a fan beam in which separate slices are radiographed while the component is rotated in small angular steps and moved linearly along the fan beam. As a result, the data collected is a series of slices of the entire component. Alternatively, acquisition can also be effected via a cone beam, where a radiation cone captures the item to be radiographed and receives separate 2-D images while the component is rotated 360° in small increments. In both cases, the accumulated raw data is then used for reconstruction algorithms to calculate and visualize the volume data.
Essentially, the basic data collection hardware components in an X-Ray inspection are: a high-power radiation source; a steering table or mechanism; and an X-ray detector. The quality of the raw data and the accuracy of all subsequent assessments are significantly affected by the sharpness of the X-ray images, and this depends largely on the quality of the source and detector, as well as the stability and sensitivity of the steering mechanism.
X-ray control in the automotive and manufacturing sectors differs slightly from those in the aerospace sector. While product safety is still very important, it is vital that any quality control procedure delivers fast and accurate results so that there is minimal downtime in production. Digital 2D radiography is often used in these sectors, but there are cases where 2D examination is not sufficient.
Similarly, failure analysis using traditional mechanical slicing destructive techniques takes a lot of time. In addition, many quality control procedures in the automotive and manufacturing sectors often look at dimensional tolerances by comparing the final product with the original CAD drawing. Traditionally this is accomplished with tactile or optical coordinate measuring machines (CMM’s). These may sometimes fail to perform the necessary metrology required for some products, especially when such products have hard-to-reach inner surfaces or have soft outer surfaces that can be deformed by tactile measurement.
The latest innovations in X-Ray inspections have brought this technology directly on to the production line. Based on proven medical technology, it introduces a new work-flow concept into the process of checking production. It features high-speed, automatic spiral CT. Here, the X-ray tube and the corresponding 64-channel gantry, the multi-line detector revolves around the product being worked on as it is carried on a conveyor belt. The reconstructed CT data of the part being analysed is automatically evaluated at the same time as the next part is loaded into the system.
For example, conventional fan can scan a cylinder head in 15 seconds using a CT rather than the usual few hours, meaning that qualitative production data is almost immediately available to be used, and should any serious defect be detected, or if any production dimension is missing, this allows the reset of parameters to be carried out quickly.
Inspections during production or post-production are cost-effective strategies and part of business risk evaluations. Effective testing provides valuable information to the next generation of design and production processes. Warranties enforce product integrity should a failure occur in the field during service. Our investment in product integrity is helping customers to stay ahead of their competition and continue to provide quality products.