2017/09/22 by J.S. Gibson, Sebastian Schröders, Gibson, James S. K. -L. +6
Engineering · #Advanced materials and composites #FOS: Physical sciences #High Temperature Alloys and Creep #Materials Science (cond-mat.mtrl-sci) #Metal and Thin Film Mechanics
paper · pdf · doi:10.48550/arxiv.1709.07714
openalex publication_date 2017/09/22 · openalex created_date 2022/08/31 · openalex updated_date 2026/07/28
Alloyed MCrAlY bond coats, where M is usually cobalt and/or nickel, are\nessential parts of modern turbine blades, imparting environmental resistance\nwhile mediating thermal expansivity differences. Nanoindentation allows the\ndetermination of their properties without the complexities of traditional\nmechanical tests, but was not previously possible near turbine operating\ntemperatures.\n Here, we determine the hardness and modulus of CMSX-4 and an Amdry-386 bond\ncoat by nanoindentation up to 1000\∘C. Both materials exhibit a\nconstant hardness until 400\∘C followed by considerable softening,\nwhich in CMSX-4 is attributed to the multiple slip systems operating underneath\na Berkovich indenter.\n The creep behaviour has been investigated via the nanoindentation hold\nsegments. Above 700\∘C, the observed creep exponents match the\ntemperature-dependence of literature values in CMSX-4. In Amdry-386,\nnanoindentation produces creep exponents very close to literature data,\nimplying high-temperature nanoindentation may be powerful in characterising\nthese coatings and providing inputs for material, model and process\noptimisations.\n