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  • Author: Robert Albrecht x
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Abstract

This paper analyses the nickel based superalloy Inconel 713C casts typically used in high and low pressure turbines of aircraft engines. The ingots were manufactured in the Research and Development Laboratory for Aerospace Materials at the Rzeszów University of Technology. The superalloy structures were analysed by the following methods: X-ray diffraction orientation measurement and ultrasonic wave propagation. Ultrasonic techniques are mainly used to measure the blade wall’s thickness. Measurement accuracy is determined by the velocity of the ultrasonic wave in the material tested. This work evaluates the effect of the nickel-based superalloy microstructure on the velocity of the ultrasonic wave propagation. Three different macrostructures: equiax (EQ), directionally solidified (DS) and single crystal (SX) were analysed. The authors determined the crystal misorientation in the obtained casts as the deviation of [001] crystallographic direction from the withdrawal axis or the main axis of the ingots. The measurements performed allowed researchers to identify significant differences in the wave velocity between EQ, DS and SX structures.

Abstract

This paper focuses on the influence of crystallographic orientation on creep resistance of CMSX-4 nickel-based superalloy. The single-crystal rods of CMSX-4 superalloy were manufactured with the use of the Bridgman method at a withdrawal rate of 3 mm/min. The crystallographic orientation of the rods was determined by the X-ray Ω-scan method with OD-EFG diffractometer and the Laue back-reflection technique. The creep tests were performed at a temperature of 982°C and the value of stress σ = 248 MPa. Microstructural investigation before and after the creep test of CMSX-4 superalloy was performed using a scanning electron microscope. The results showed that the distribution of the values of α angle strongly affects the creep resistance of a single-crystal superalloy.