Advanced NDT with high resolution Computed Tomography

In today’s quality market, achieving the smallest feature recognition possible in the inspection process has become a higher priority than ever before. Due to complex geometries and miniaturization of many high reliability components in the automotive, electronics and aerospace industries, achieving this level of feature recognition has also become increasingly difficult. Due to inherent limitations, many of the inspection requirements can no longer be satisfied with conventional X-ray inspection methods such as 2D X-ray inspection. For example, the depth of detail is not quantifiable, which in some cases can be vital to the manufacturing process. High resolution Computed Tomography (CT) presents an effective method of mapping the internal structure of components in three dimensions. With this technique, any internal difference that corresponds to a contrast in material, density or porosity can be visualized and measured. These properties allow the use of CT as an NDT tool, permitting examination of samples for internal porosity, cracks, delamination, inclusions and mechanical fit. CT techniques are used to measure internal distances or the internal wall thickness of complex castings and areas which are often inaccessible for optical scanners or conventional tactile coordinate measurement machines (CMM). The CT volume data provides information for reverse engineering or first article inspection of the entire part by merging it with the CAD model to generate a variance map of both data sets. Combined these capabilities contribute to early detection of process and product weaknesses therefore increasing yield and productivity. Modern microfocus and nanofocus systems are not only suitable for examinations of low absorbing materials like synthetics, but also for the analysis of the internal microstructure of higher absorbing metal castings, ceramics or composites containing high absorbing particles. High resolution CT widely expands the spectrum of X-ray detectable defects in process control and failure analysis increasing reliability and safety of components for, e.g., automotive, aerospace, and military applications. It opens a new dimension for 3D quality assurance and will partially replace destructive methods like cross-sectioning – saving costs and time per