0434712 - ÚFM 2015 RIV SK eng J - Journal Article
Luptáková, Natália - Král, Petr - Dymáček, Petr
The influence of high temperature on the microstructure properties of Ni-based superalloy.
Powder Metallurgy Progress. Roč. 14, č. 4 (2014), s. 190-198. ISSN 1335-8987.
[Deformation and Fracture in PM Materials. Stará Lesná, 26.10.2014-29.10.2014]
R&D Projects: GA MPO FR-TI4/406; GA MŠMT(CZ) ED1.1.00/02.0068
Institutional support: RVO:68081723
Keywords : powder materials * Ni-based PM superalloy * grip of creep machine * oxidation
Subject RIV: JG - Metallurgy

The PM Ni-15Cr-18Co-4Al-3.5Ti-5Mo alloy is a high temperature resistant superalloy with high mechanical, chemical and thermal properties. This makes the material ideal for high performance engine parts, high temperature resistant machine parts, etc. This superalloy was used as grips of the creep machine. The material was exposed at 1100 ° C for about 10 days at 10 MPa stress. During the creep test occurred unacceptable creep deformation of grips as well as severe surface oxidation with scales peeling off. The three types of PM samples have been studied: initial, heat treated (annealing - 10 min/1200 °C) and after using as a part of the equipment of the creep machine during the creep test. Phase (CoNi2)Ti particles preferentially created at the grain boundaries of the samples after performing creep tests. As a result of this process, grain boundaries are deprived of Ti. Moreover, its presence at the grain boundaries caused reduction of the hardness of the material. The Vickers hardness test was used to measure hardness on the samples before and after the creep test. The value of the sample hardness after the creep test has decreased by ~ 70 HV 5. On the basis of the experiments and obtained results, the given material is not recommended to be used for grips of creep machine at a temperature above 1000 °C.
Permanent Link: http://hdl.handle.net/11104/0238690