Influence of powder metallurgy route on precipitation processes in MgTbNd alloy

Solution treated MgTb3Nd2 alloy (nominal composition in wt.%) (ST) and the alloy prepared by hot extrusion of isostatically pressed powder (PM) were isochronally heat treated and studied by electrical resistivity and hardness measurements and by differential scanning calorimetry. Microstructure deve...

Full description

Saved in:
Bibliographic Details
Published in:Materials characterization 2016-02, Vol.112, p.149-154
Main Authors: Stulikova, Ivana, Smola, Bohumil, Vlach, Martin, Kudrnova, Hana, Piesova, Jaroslava
Format: Article
Language:English
Subjects:
ACTIVATION ENERGY
ANNEALING
CALORIMETRY
Differential scanning calorimetry
Electrical resistivity
Electron microscopy
FCC LATTICES
HARDNESS
Hardness measurement
Hot extrusion
MAGNESIUM ALLOYS
MATERIALS SCIENCE
MICROSTRUCTURE
NANOSCIENCE AND NANOTECHNOLOGY
Phases
POWDER METALLURGY
PRECIPITATION
Resistivity and hardness measurements
TEMPERATURE RANGE 0400-1000 K
THERMAL ANALYSIS
TRANSMISSION ELECTRON MICROSCOPY
VICKERS HARDNESS
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Solution treated MgTb3Nd2 alloy (nominal composition in wt.%) (ST) and the alloy prepared by hot extrusion of isostatically pressed powder (PM) were isochronally heat treated and studied by electrical resistivity and hardness measurements and by differential scanning calorimetry. Microstructure development was investigated in transmission electron microscopy. Successive precipitation of transient phases in the sequence β″ (D019 plates)→β′(cbco)→β1 (Mg3Gd type, fcc)→β (Mg5Gd type, fcc) known from the ST alloy was identified also in the PM alloy. The early precipitation stage (D019 clusters) revealed in the ST alloy as well as precipitation of equilibrium βe phase Mg41(Tb,Nd)5 manifest themselves only slightly in the PM alloy. Powder metallurgy route does not change the values of activation energies but shifts the temperature ranges of these processes. Vickers hardness of the as prepared state is higher in the PM alloy and is very resistant against the heat treatment up to 510°C. Contrary to the ST alloy precipitation due to isochronal annealing does not lead to pronounced hardness changes in the PM alloy. •Powder metallurgy (PM) does not change precipitation sequence in MgTbNd alloy.•Temperature ranges of transient phase precipitations are shifted in PM alloy.•Hardness is resistant against isochronal heat treatment up to 510°C in the PM alloy.•PM procedure does not change activation energies of precipitation.
ISSN:1044-5803
1873-4189
DOI:10.1016/j.matchar.2015.12.020