Technology X-ray measurement lowers cost, time of tooling adjustments
A trio of companies reports on the benefits of highly automated 3D computed tomography in component qualification and tool error correction for light metal and plastic injection moulding.
In addition to today's widespread use of high-resolution computed tomography (CT) in quality control, this technology's continued development has taken a giant leap forward and is now being used in measuring procedures. Three-dimensional metrology using CT can non-destructively measure plastic and light metal components which, until recently, were not able to be inspected and measured using current methods due to their complex internal structures. This article seeks to provide an overview of the current situation regarding CT technology and 3D metrology software. It also offers concrete examples from the automotive industry to illustrate the time-and-cost benefits that result from using largely automated CT measuring routines that are carried out as part of component qualification and tool and mould correction.
Detecting the entire surface area using a CT scan
For the subject at hand, the actual physical measurement is performed by scanning a series of 2D X-ray projection images. For this, the specimen is positioned on a precision manipulation system and is completely rotated through 360 degrees on a precision rotation platform during the measurement. The quality of the raw data – and naturally the accuracy of all subsequent evaluations of the digitally reconstructed 3D volume – is strongly influenced by the sharpness of the X-ray images, which is heavily dependent on the quality of the X-ray source and detector, including the precision and stability of the manipulation system. One could therefore say: the more effectively the CT measurement system performs this first step, the more precisely the measurement task can be performed.