Influence of Mo alloying on the thermal stability and hardness of ultrafine-grained Ni processed by high-pressure torsion

Authors: Kapoor, G., Huang, Y., Sarma, V.S., Langdon, T.G. and Gubicza, J.

Journal: Journal of Materials Research and Technology

Volume: 6

Issue: 4

Pages: 361-368

ISSN: 2238-7854

DOI: 10.1016/j.jmrt.2017.05.009

Abstract:

The influence of Mo alloying on the thermal stability of grain size, dislocation density and hardness of ultrafine-grained (UFG) Ni alloys was studied. The UFG microstructure in alloys with low (∼0.3 at.%) and high (∼5 at.%) Mo contents was achieved by high-pressure torsion (HPT) performed for 20 turns at room temperature. The thermal stability of the two alloys was studied by calorimetry. A Curie-transition from ferromagnetic to paramagnetic state was not found for the Ni–5% Mo alloy due to the high Mo content. It was found that heating at a rate of 40 K/min up to ∼850 K resulted in a complete recovery and recrystallization of the UFG microstructure in the alloy with 0.3% Mo. The same annealing for Ni–5% Mo led only to a moderate reduction of the dislocation density and the grain size remained in the UFG regime. Therefore, the higher Mo content yielded a much better thermal stability of the Ni alloy. The influence of the change of the microstructure during annealing on the hardness is discussed.

Source: Scopus

Influence of Mo alloying on the thermal stability and hardness of ultrafine-grained Ni processed by high-pressure torsion

Authors: Kapoor, G., Huang, Y., Sarma, V.S., Langdon, T.G. and Gubicza, J.

Journal: JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T

Volume: 6

Issue: 4

Pages: 361-368

eISSN: 2214-0697

ISSN: 2238-7854

DOI: 10.1016/j.jmrt.2017.05.009

Source: Web of Science (Lite)