Numéro
J. Phys. IV France
Volume 03, Numéro C7, Novembre 1993
The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
Page(s) C7-331 - C7-334
DOI http://dx.doi.org/10.1051/jp4:1993749
The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés

J. Phys. IV France 03 (1993) C7-331-C7-334

DOI: 10.1051/jp4:1993749

Effects of composition on degree of order and ordering kinetics of Ni-Cr based superalloys

A. MARUCCO

CNR-ITM, Via Induno 10, 20092 Cinisello B., Milano, Italy


Abstract
The ordering behaviour of different Ni-Cr base alloys, isothermally aged in the 450-600°C temperature range for up to 32000 h, was investigated by electrical resistivity measurements, lattice parameter determinations by X-ray diffraction and TEM observations. Degree of order and ordering kinetics were observed to depend on chemical composition, ageing time and temperature : SRO develops in all alloys during cooling from solution temperature and early stages of ageing with resistivity increments by up to 7% and lattice contractions by up to 0.05%. After 30000 - 32000 h ageing at temperatures below 500°C SRO transform to LRO in Brightray S, Nimonic 80A and Inconel 690 with sharp resistivity decreases of up to 16% and lattice contractions of up to 0.12%, whereas in the other alloys examined in this work only SRO structure was observed.



© EDP Sciences 1993