Industrial CT Measuring and Data Evaluation: Additive and Composite Part Inspection and Metrology
Innovation reaching new speeds
When designing the fastest electric race cars in the world, quality can’t be second-guessed. Swiss AMZ (Akademischer Motorsportverein Zürich), comprised of 30 ETH Zurich and HSLU Lucerne engineering students, develops, designs and manufactures world record-holding race cars that compete internationally against teams from other universities.
Using leading-edge technologies, such as additive manufacturing with selective laser melting (SLM), they often create or adapt their own components. In a vehicle that accelerates from 0-100 km/h in 1.5153 seconds, component distortion and wear are serious safety issues that can make or break their project.
Non-destructive testing (NDT) and 3D metrology are thus integral parts of the development process, and the students work closely with expert Swiss industrial CT measuring and data evaluation company MessX which uses GE Inspection Technologies’ phoenix v|tome|x m micro- and nanoCT systems for 3D computed tomography evaluations.
MessX carried out CT testing on several components, including an additive-manufactured upright wheel carrier that must withstand extreme loads, and an AMZ-developed, handcrafted, foam-filled Carbon Fiber Reinforced Polymer (CFRP) wheel rim.
For the wheel carrier, distortion and pores can critically impact the strength of the component. Using CT scans and data prepared by MessX, 3D porosity analyses automatically determined the sizes of the largest pores, as well as their positions. The scans also enabled the manufactured part to be compared to the CAD model and provided key insight into the impact of distortion on the material strength.
The complex manufacturing process for the CFRP rims, which enable a 40% reduction in rotating mass compared to off-the-shelf parts, meant NDT testing was essential. High resolution CT scans provided 3D insights into the structure of the rims, the layer build-up in laminated curves and edges, and the spots where the material transitioned from carbon fabric to foam core.
BHGE Inspection Technologies’ Contribution
To carry out the CT scans, MessX used one of its BHGE Inspection Technologies’ phoenix v|tome|x m industrial CT scanners. This versatile microfocus Computed Tomography system for highly precise 3D metrology and analysis detects details down to < 1 µm.
Even for the wheel carrier part (160 x 140 x 120 mm), the resolution allowed to localize and analyze all pores being relevant for strength.
The analysis of the CT data for the wheel carrier revealed pores of more than 0.5 mm, which led the AMZ team to produce new parts using a different alloy. The comparison of the physical and CAD parts also led to the development of a new clamping design and milling procedure.
For the rims, the CT scans and analysis confirmed defects such as dry spots on the surface, and provided insight and learning. Following a major redesign the next year, and the very successful NDT experience with MessX and its phoenix v|tome|x m, AMZ will repeat the scanning exercise, to verify the manufacturing and to document the wear on the rims during testing.
The team is confident that the continued collaboration and testing will help prevent damage to the rims of these innovative electric cars in future races.