A team of researchers from the Department of Electronic Instruments and Devices of ETU “LETI” has developed a device for controlling the quality of single-crystal turbine blades production. This is a new type of X-ray equipment, which is unique in Russia and the world today. Currently, X-ray methods are used for this purpose in general-purpose diffractometers, large stationary devices, which only large laboratories can afford. Such equipment is universal and allows testing the quality of almost any single-crystal product. However, there is no need for such versatility at specialized factories.
The purpose of the development of ETU “LETI” researchers is to solve the problems of such productions. The work of a device is based on the Laue method. The equipment allows testing the quality of one blade up to several hundred mm in a few minutes. The turbine blades need to be monitored in large quantities, and the new device is designed for this specific task. The blades are made by casting with special molds, then the technologist examines each finished product and marks “suspicious” points. He then passes on the piece to a machine, which makes the necessary measurements at each of the marked spots.
“X-ray radiation, like any other electromagnetic wave, has the properties of diffraction and interference. If we direct a narrow beam of X-ray radiation to a single crystal, then, depending on the angle at which this beam falls, the crystal can reflect it at the same angle. There is such an incorrect phrase “the angle of incidence is equal to the angle of reflection” – in our case it is the opposite. The resulting pictures from Laue’s reflected spots are individual for each particular case. This is what our analysis is based on. We obtain images of spots on a twin-axis digital X-ray detector and, analyzing the position of each spot, we can conclude: is it a perfect crystal or an imperfect crystal, whether it grew “correctly” or “incorrectly”, whether there are defects in its planes or not. A unique computer program evaluates all this is and gives the result”, says Nikolay Potrakhov, Department of Electronic Instruments and Devices of ETU “LETI”
This fully domestic equipment has already been delivered to the UEC-Perm Engines Company and Salut Enterprise. The device is relatively cheap; its cost is several million rubles. This equipment can be installed in almost any laboratory or production facility. China’s factories are also interested in it. The first device from ETU “LETI” will be sent abroad in early April.