| |
Testing of turbochargers Application report by PRAE-TURBO GmbH & Co. KG and Rohmann GmbH
One of the zones of these centrifugal compressors subject to the greatest strain is the area of the central bore, which connects the compressor to the shaft of the turbocharger. Due to a defect whereby a crack in this critical area of the compressor led to the breakdown of the turbocharger, a testing procedure using eddy current technology was developed in cooperation with Rohmann GmbH. In order to check the error signals, the manufacturer conducted extensive material inspections on the test pieces and detected a segregation (segregation consisting of titanium depending upon the production) running through the fracture pattern which caused the final crack in the compressor as a result. Using a rotating test probe with a corresponding manipulator, the segregations in the centrifugal compressors were able to be detected before the finishing operations were conducted on a CNC milling machine. Not only does this mean that the individual batches can be checked for segregations, but it also saves expensive and extensive CNC machining. During the testing at different measuring depths, eddy current signals clearly showed titanium segregation which enabled the defect location to be precisely located in the inspected bore. According to the knowledge gained about the use of eddy current testing for the detection of material segregations, it will now take less time to test centrifugal compressors produced in the future and that will therefore prevent a crack in the centrifugal compressor while it is in operation. The article was able to published through close cooperation with graduate engineer Ms. Angela Au (Head of Materials Engineering at PRÄWEST) and graduate industrial engineer Mr. Stephan Reich (Head of Quality Assurance at PRAE-TURBO GmbH & Co. KG) |
Download Flyer