锥束扫描三维CT及其工程应用

Three Dimensional Computed Tomography Based on Cone-beam Scanning and Its Engineering Application

Objective: To introduce the authors research work of 3D-ICT (Three Dimensional Industrial Computed Tomography) and ICT assisted reverse engineering. Methods: On the basis of the amorphous silicon flat panel detector (FPD) with high resolution, sensitivity and wide dynamic range, the cone-beam 3D-ICT is researched. The cone-beam X-ray scans the objects along circle locus and the two dimensional digital projections are captured by the FPD. Then using the projections, the 3D-images are reconstructed, which are almost as good as 2D-CT images when the cone-beam angle is small enough. Through corresponding image and graphics processing methods on the 3D-CT images, the internal and external contours of the object are got and loaded into CAD designing platform. Using the RE module of the software, the CAD model of the physical prototype is finally created. Conclusion: The experimental results on low and high X-ray energy (320KV&9MeV) prove that the image quality of 3D-CT can almost be as good as 2D-CT, the spacial resolution is 2.0-3.0Lp/mm and the contrast resolution is 0.3%. ICT assisted RE is the powerful approach to rapid prototype manufacturing(RPM),technique decoding and remodeling of objects with complicated external and internal surfaces, and will be of important value and wide using foreground.