Micro CT overview
Micro CT was initially developed for medical applications for healthcare purposes. With the improvements in technology and advancements in computerized detector panels and software, micro computed tomography took off for industrial applications. Prevalent in the industry today, micro CT is used for qualification and validation of aerospace components, automotive parts and medical devices. Industry leaders seek outsourced nondestructive testing labs to conduct a speedy and accurate microtomography scan for failure investigations, part geometry and internal part analysis.
What is Micro CT?
Micro CT, also known as micro CT, high resolution CT, x-ray micro CT, or microtomography, is a nondestructive method of inspection for internal and external analysis of solid subjects, based on radiographic testing techniques. Similar to the medical concept of computed axial tomography (CAT) scan, micro CT captures 2D x-ray images which are re-constructed to develop a 3D model, using a specialized software.
Micro Computed Tomography is a testing technique, providing users with extremely high resolution with exceptional internal detail. Conventional Computed Tomography differs from micro tomography, as micro CT can provide results with a much higher resolution or voxel size, providing improved detectability and exceptional accuracy. This is because of the use of micro focus x-ray energy source.
How Micro CT works
Micro computed tomography utilizes x-ray technology in combination with a specialized software to develop a 3D rendering, with internal and external structures reflecting the scanned object. Using an x-ray source, a computerized detector panel and a specialized software to compute the data and reconstruct the x-ray tomography images, a Micro-CT scanner provides high resolution results.
X-ray source: The x-ray source for micro CT, or high resolution CT is a micro focus energy source. Micro focus CT allows users to obtain high detail results, although it utilizes less energy and is developed to scan small to medium sized objects. For example, aluminum castings can be scanned using a micro focus CT system, allowing viewers to access internal geometry and failures such as porosity, with very high resolution or voxel size. Comparative to conventional testing x-ray sources, micro focus generates a narrow, micro sized focal point which provides improved accuracy and detectability.
Computerized detector panel: The detector panel is placed on the opposite side of the x-ray source, so all radiation is directed toward the recording medium. The object to be scanned is placed between the x-ray source and the detector panel. A detector panel, commonly a CCD camera, is utilized to capture and transform the x-ray energy into 2D cross sectional images. These images are captured at pre-determined increments, as the object rotates 360 degrees.
Specialized software: A software is utilized to compute the data and images captured by the detector panel, in order to stack all the 2D cross sectional x-ray slices and develop a 3D rendering. The 3D model is further utilized for extensive internal and external part analysis, including failure investigation, dimensional analysis and wall thickness.
Radiographic Testing Technique
Although there are several different radiographic testing techniques, for the purpose of micro-CT, x-radiation is utilized. Other forms of radiography include gamma radiation and neutron radiation. X-ray sources rely on electricity to generate radiation. The concept of x-rays involve the acceleration of electrons, which forcefully decelerate when they come into contact with an atomic particle. For microtomography, electrically powered x-ray sources generate radiation, which is captured and reconstructed into usable data.