Anwendungsgrenzen von modernen Nickelbasis-Superlegierungen in effusionsgekühlten Bauteilen zukünftiger Gasturbinen
type: CreativeWork
description: The deformation and damage behaviour of two nickel-base superalloys, CMSX-4 and SX CM186LC, have been investigated. Hot-tensile, tensile creep and low-cycle-fatigue tests have been performed on single crystal and directionally solidified variants at temperatures up to 1000°C to compare their tensile-, creep- and fatigue behaviour. The strength and fatigue properties of both materials were significantly influenced by their different microstructures. Comparing the single crystal materials, CMSX-4 exhibited in strain rate controlled tensile tests (1000°C) higher strength properties than SX CM186LC. The heterogeneity of the microstructure development of SX CM186LC favoured crack initiation and explains the worse fatigue behaviour. Crack growth followed mainly in the interdendritic regions. In the temperature range of 750 to 1000°C, the creep resistance of SX CM186LC was lower than that of CMSX-4. In isothermal fatigue tests the advantage of the single crystal variants compared to the directionally solidified variants was demonstrated. Bond coating of MCrAlY on single crystal specimens seemed to have a positive effect on life time compared to directionally solidified variants. The difference in the materials behaviour could be clearly demonstrated by a comparison between the homogeneous microstructure of CMSX-4 and the heterogeneous microstructure of SX CM186LC. Based on some oxidation test results mentioned in the open literature together with isothermal oxidation tests carried out in a temperature range of 550 to 1000°C, CMSX-4 exhibited good oxidation resistance, which meant that the cooling channels (drillings) did not close up due to oxide scale formation. Principally this work concentrated on the set-up and testing method for in-situ investigations in the scanning electron microscope (SEM). In-situ investigations in the SEM were carried out to obtain a description of micro-crack (smaller than 100 µm) initiation and growth, starting from laser drilled cooling channe…
abstract: The deformation and damage behaviour of two nickel-base superalloys, CMSX-4 and SX CM186LC, have been investigated. Hot-tensile, tensile creep and low-cycle-fatigue tests have been performed on single crystal and directionally solidified variants at temperatures up to 1000°C to compare their tensile-, creep- and fatigue behaviour. The strength and fatigue properties of both materials were significantly influenced by their different microstructures. Comparing the single crystal materials, CMSX-4 exhibited in strain rate controlled tensile tests (1000°C) higher strength properties than SX CM186LC. The heterogeneity of the microstructure development of SX CM186LC favoured crack initiation and explains the worse fatigue behaviour. Crack growth followed mainly in the interdendritic regions. In the temperature range of 750 to 1000°C, the creep resistance of SX CM186LC was lower than that of CMSX-4. In isothermal fatigue tests the advantage of the single crystal variants compared to the directionally solidified variants was demonstrated. Bond coating of MCrAlY on single crystal specimens seemed to have a positive effect on life time compared to directionally solidified variants. The difference in the materials behaviour could be clearly demonstrated by a comparison between the homogeneous microstructure of CMSX-4 and the heterogeneous microstructure of SX CM186LC. Based on some oxidation test results mentioned in the open literature together with isothermal oxidation tests carried out in a temperature range of 550 to 1000°C, CMSX-4 exhibited good oxidation resistance, which meant that the cooling channels (drillings) did not close up due to oxide scale formation. Principally this work concentrated on the set-up and testing method for in-situ investigations in the scanning electron microscope (SEM). In-situ investigations in the SEM were carried out to obtain a description of micro-crack (smaller than 100 µm) initiation and growth, starting from laser drilled cooling channe…
author: Klabbers-Heimann, Jürgen Johannes
language: ger
keywords: info:eu-repo/classification/ddc/620, Ingenieurwissenschaften, Nickelbasis-Superlegierung, Effusionskühlung, Gasturbine
date published: 2002
date modified: 2026-07-30T19:43:19Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University