3D imaging by X-ray computed tomography is a non-destructive way to examine the internal features or structure of a component or assembly. It is a key enabling tool for defects inspection, failure analysis, quality control, product verification and reverse engineering.
X-ray computed tomography, often referred to as XCT or simply CT, works by recording the quantity of X-ray energy transmitted through the sample or component as it is rotated. In a typical case anywhere from 180 to 3600 transmission X-ray images are collected during a single 360° scan. From this set of projection images reconstruction algorithms can create cross-sectional slices through the sample perpendicular to the axis-of-rotation. These cross-sectional slices can be stacked to form a 3D model of the sample. Subsequently visualisation tools can be used to manipulate and examine the 3D model from any orientation or viewpoint. Both inspection and measurement tasks can be implemented depending on the specific application.
Typical applications of X-ray CT and 3D visualisation include
- Quality Control
- Internal Structure / Damage Inspection
- Failure Analysis
- Product Design Verification
- First Article Inspection
- Reverse Engineering
- Assembly / Disassembly Assessment
The main benefits include the non-destructive nature of the inspection or measurement process, the ability to assess both internal and external features in a single CT scan, and the provision of high and uniform data density almost regardless of component complexity. Using SIMTech technologies in this area also provides the benefit of flexibility for application-specific customisation of data acquisition, reconstruction and visualisation.
9.15am - 9.30am Registration
9.30am – 9.50am CT system and CT reconstruction
by Dr Liu Tong, Senior Research Engineer, SIMTech
9.50am – 10.10am 3D X-Ray image visualization software
by Dr Yin Xiaoming, Senior Research Engineer, SIMTech
10.10am – 10.40am Visit to X-ray lab and hands on 3D image visualization software.
10.40am – 11.15am Tea Break & Round-table discussion
CT system and CT reconstruction
X-ray computed tomography (XCT or CT) requires three main building blocks;
- Data Acquisition
Data acquisition is supported by SIMTech for a wide range of component sizes, geometric complexity and material compositions.
Large and dense samples can be scanned using an in-house developed high energy CT system which offers dual X-ray sources operating at 225 kV and 450 kV mounted on a multiple-axis manipulator system together with a large flat panel direct digital detector. Material penetration equivalent to 70 mm of steel or 280 mm of aluminium can be achieved for samples up to 500 x 500 x 500 mm in size and 50 kg in weight. The maximum achievable voxel resolution is in the range of 25-250 microns depending on object size, geometry and composition.
Smaller samples can be scanned using the Yxlon Y.Fox 160.25 Nano-focus X-ray Inspection Machine which operates at energy levels up to 160 keV.
Reconstruction of the CT volume from a series of projection images is performed using a proprietary implementation of the Feldkamp-Davis-Kress filtered back projection algorithm. SIMTech’s PowerRecon software implements both conventional and custom planar versions of the FDK algorithm. PowerRecon planar reconstruction is optimised for reconstruction of objects that have high aspect ratios such as semiconductor devices. This optimised reconstruction can either reduce the necessary reconstruction time or, alternatively, can be used to increase the reconstruction resolution. The software also incorporates several patented methods for reconstruction alignment and system calibration. The software is designed to be user-friendly whilst allowing access to the algorithm control parameters for maximum flexibility of operation.
3D X-Ray image visualisation software
Using SIMTech’s volume visualisation software, 3DiPAM, the three-dimensional structure of the reconstructed volume is easily analysed for pores, cracks and other forms of defect. The CT volume can be manipulated in both 2D and 3D spaces and rendered for viewing as a 3D object. User-defined sections of the sample can be cut away or made transparent to allow examination of internal features. The orientation of the object model can be carefully controlled allowing easy extraction of preferred slices and accurate measurements to be obtained. In-built image processing tools can be used to improve the quality of the CT images by removing noise and highlighting relevant features of the sample. Segmenting images into different components or for defect detection can be achieved manually or automatically. Surface models of defects can be generated and visualised in 3D to study the shape, size and distribution of the defects. For reverse engineering applications surface models of the 3D CT volume can be exported in STL format.
Who Should Attend
SME and MNC working in the area of failure analysis, product verification, quality control and reversing engineering for precision engineering, marine, oil & gas and aerospace industry.
This complimentary seminar is free of charge. Seats are available on first-come, first-served basis. To reserve a place, please register online.
For technical enquiries: Dr Ng Teck Chew, Scientist, Mechatronics Group, Tel: 6793 8261; Email: tcng@SIMTech.a-star.edu.sg
For general enquiries: Chloe Lim Li Li Email: email@example.com
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