Abstract: A turbocharger turbine rotor includes a rotor basic body, and moving blades configured without an outer shroud. The moving blades, forming a defined curvature region, merge into the rotor basic body with a defined, constant or variable curvature radius rf. On a first group of first moving blades, the following relationship applies to the curvature radius of the curvature region of the first moving blades: 2.5%?rf1*100/l?10%, wherein rf1 is the constant or variable curvature radius of the curvature region of the first moving blades and l the length of the first moving blades on a flow trailing edge. On a second group of second moving blades, the curvature radius rf2 of the curvature region of the second moving blades deviates from the curvature radius rf1 of the curvature region of the first moving blades on the damping side in a defined manner.

Abstract: A method for selecting a mistuning pattern of a turbomachine rotor disk includes providing information items relative to boundary conditions of a rotor disk excitation by forced vibrations; providing a reduced-order model of the rotor disk; producing a multiplicity of mistuning patterns of the rotor disk by entering the information items and the reduced-order model into a multi-objective optimizer and producing the mistuning patterns by the multi-objective optimizer while optimizing stability of the system in relation to self-excited vibrations while simultaneously optimizing stability of the system relative to forced vibrations. For each mistuning pattern produced, the reduced-order model is applied to a rotor disk, which implements the produced mistuning pattern, and the properties of this rotor disk are determined in view of self-excited vibrations and in view of forced vibrations. One of the mistuning patterns is selected for implementation.

Abstract: In the manufacture of integrally designed rotor wheels (BLISKs), the natural frequency of each blade is measured after forming by conventional shaping methods and the respective blade mass and its divergence from the smallest blade mass is calculated therefrom. The mass of each blade exceeding the smallest blade mass is removed by means of an etchant, so that all blades have essentially corresponding thickness, chord length, mass and natural frequency and are evenly loaded in operation. BLISKs manufactured in this way feature a long service life.

Abstract: For determining production-inherent mistuning of integrally manufactured rotor wheels (blisks) on the basis of the identification of blade natural frequencies, the individual blades are excited independently of each other and the vibratory response is measured for the calculation of the respective blade natural frequency and of mistuning. During measurement the blades not under investigation are additionally mistuned by temporarily applying an identical extra mass to each of them, such that coupling effects disturbing the measurement of the vibratory response of the excited blade are shifted away from the natural frequency-near range of the blades and hence eliminated.

Abstract: For determining production-inherent mistuning of integrally manufactured rotor wheels (blisks) on the basis of the identification of blade natural frequencies, the individual blades are excited independently of each other and the vibratory response is measured for the calculation of the respective blade natural frequency and of mistuning. During measurement the blades not under investigation are additionally mistuned by temporarily applying an identical extra mass to each of them, such that coupling effects disturbing the measurement of the vibratory response of the excited blade are shifted away from the natural frequency-near range of the blades and hence eliminated.

Abstract: A silicon wafer having no epitaxially deposited layer or layer produced by joining to the silicon wafer, with a nitrogen concentration of 1·1013-8·1014 atoms/cm3, an oxygen concentration of 5.2·1017-7.5·1017 atoms/cm3, a central thickness BMD density of 3·108-2·1010 cm?3, a cumulative length of linear slippages ?3 cm and a cumulative area of areal slippage regions ?7 cm2, the front surface having <45 nitrogen-induced defects of >0.13 ?m LSE in the DNN channel, a layer at least 5 ?m thick, in which ?1·104 COPs/cm3 with a size of ?0.09 ?m occur, and a BMD-free layer ?5 ?m thick. Such wafers may be produced by heat treating the silicon wafer, resting on a substrate holder, a specific substrate holder used depending on the wafer doping. For each holder, maximum heating rates are selected to avoid formation of slippages.

Abstract: In the manufacture of integrally designed rotor wheels (BLISKs), the natural frequency of each blade is measured after forming by conventional shaping methods and the respective blade mass and its divergence from the smallest blade mass is calculated therefrom. The mass of each blade exceeding the smallest blade mass is removed by means of an etchant, so that all blades have essentially corresponding thickness, chord length, mass and natural frequency and are evenly loaded in operation. BLISKs manufactured in this way feature a long service life.

Abstract: A silicon wafer having no epitaxially deposited layer or layer produced by joining to the silicon wafer, with a nitrogen concentration of 1·1013-8·1014 atoms/cm3, an oxygen concentration of 5.2·1017-7.5·1017 atoms/cm3, a central thickness BMD density of 3·108-2·1010 cm?3, a cumulative length of linear slippages ?3 cm and a cumulative area of areal slippage regions ?7 cm2, the front surface having <45 nitrogen-induced defects of >0.13 ?m LSE in the DNN channel, a layer at least 5 ?m thick, in which ?1·104 COPs/cm3 with a size of ?0.09 ?m occur, and a BMD-free layer ?5 ?m thick. Such wafers may be produced by heat treating the silicon wafer, resting on a substrate holder, a specific substrate holder used depending on the wafer doping. For each holder, maximum heating rates are selected to avoid formation of slippages.