Title :
Consolidation, magnetic and mechanical properties of gas atomized and HDDR Nd2Fe14B powders
Author :
Horton, J.A. ; Heatherly, L. ; Branagan, D.J. ; Sellers, C.H. ; Ragg, O. ; Harris, I.R.
Author_Institution :
Div. of Metals & Ceramics, Oak Ridge Nat. Lab., TN, USA
fDate :
9/1/1997 12:00:00 AM
Abstract :
Nd2Fe14B powders produced by gas atomization (GA) were consolidated and the fracture toughness and magnetic properties were measured and compared to material produced by hydrogenation, disproportionation, desorption, and recombination (HDDR) and to Magnequench MQII magnets. Hot pressing of the gas atomized powder without TiC additions required temperatures and times similar to that required by Magnequench melt spun powder. Titanium plus carbon additions, which result in enhanced quenchability during production of the GA powder, required higher temperatures than alloys without TiC for successful hot pressing and full densification. However, grain sizes remained under 50 nm in the consolidated magnet. Toughnesses for both HDDR and GA material with the larger powder sizes were slightly higher than those of comparable MQII specimens. The TiC modified GA material may result in tougher magnets that are easier to process at higher temperatures by techniques such as extrusion
Keywords :
boron alloys; densification; ferromagnetic materials; fracture toughness; grain growth; grain size; hot pressing; iron alloys; neodymium alloys; permanent magnets; powder metallurgy; 50 nm; C additions; HDDR Nd2Fe14B powders; Magnequench MQII magnets; Magnequench melt spun powder; Nd2Fe14B; Nd2Fe14B-TiC; Ti additions; TiC; TiC modified GA material; consolidation; desorption; disproportionation; enhanced quenchability; extrusion; fracture toughness; full densification; gas atomized Nd2Fe14B powders; grain sizes; higher temperatures; hot pressing; hydrogenation; magnetic properties; mechanical properties; powder sizes; recombination; Atomic measurements; Iron; Magnetic materials; Magnetic properties; Magnets; Mechanical factors; Neodymium; Powders; Pressing; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
