Magnetics Business & Technology - Summer 2018 - 34

SPONTANEOUS THOUGHTS

a Column by Dr. Stan Trout

Dysprosium 2.0
A little over five years ago I wrote a column called Dysprosium 2.0.
Element number 66 has been in focus lately due to some forecasts about availability in light of some new applications. Adamas
predicts a 30% shortage of Dy by 2025. It seems like an appropriate time to look at the situation again.
The final conclusion of the Adamas report is, "If automakers,
motor manufacturers, and other end-users of high-temperature
NdFeB do not act today to secure long-term supplies, they will
soon find themselves amidst a sellers' market scrambling for rare
earth motor metals the same way many are scrambling today for
battery metals."
We'll come back to this point later.
Just as a refresher, the four eras I defined previously to describe
the use of dysprosium in NdFeB magnets are as follows:
1.0 The initial discovery that Dy can increase the HcJ of NdFeB
magnets, which in turn allows higher operating temperatures. This
happened very early, circa 1983.
1.1 The realization that other alloying elements such as niobium
and cobalt can reduce, but not eliminate, the need for Dy. We also
learned that terbium works a bit better than Dy in increasing HcJ,
but Tb is usually not as cost effective. This was 1990 to about
2005.
1.2 The development of Grain Boundary Diffusion (GBD) technology. This technology puts dysprosium preferentially in the grain
boundaries and their adjoining regions, not throughout the alloy,
as was the original practice. It achieves the same effect, i.e. increased HcJ, with roughly 50% less Dy. This technology has been
in use since approximately 2005.
2.0 A combined strategy based on the following five significant
features:
1.) A search for more resources;
2.) Increased interest in recycling;
3.) Widespread application of Dy reduction technology, i.e. Dys
prosium 1.2;
4.) A search for new magnets without Dy;
and
5.) Designs minimizing the use of Dy
Dysprosium 2.0 has been going on since about 2010.

rare earths have been relatively low for the past few years, investment in these projects has been minimal. The important point is
we have better knowledge about the location of potentially viable
deposits. Activity would likely return as soon as Dy prices climb.
2.) Recycling activities are taking place on a limited scale. In other
words, we have started, but we still have a way to go to reach
sustainability.
3.) Today many magnet companies offer GBD grades of NdFeB.
There are many patents on the various ways to put Dy preferentially in the grain boundaries of NdFeB magnets. In my experience, they all seem to work. Because some extra processing is
involved, there is a small price premium to GBD grades. This has
caused some users to either delay qualification or implementation
of designs using GBD grades. But my impression is that this is a
change which could be done quickly, if warranted.
4.) Research in finding magnets without Dy has moved forward in
several directions, such as substituting other rare earths, FeN materials and even new ferrite compositions have appeared. While
some of these projects show promise, none has displaced Dycontaining grades of NdFeB.
5.) Even though it may not be considered as sexy as the other options, there has been good progress on the design front. Common
approaches include optimizing designs to use less Dy, lowering
the maximum temperature of the design (a special thanks to everyone who took my advice on this topic), using a combination of
the two, or even engineering a SmCo or ferrite-based alternative
design.
So should we be afraid of a looming dysprosium shortage? I am
not as worried as the folks at Adamas. Let me explain why.
Recently I watched the documentary film Saving the Great Swamp,
Battle to Defeat the Jetport. It details the struggle between the
Port Authority of New York & New Jersey (PANYNJ) and an ad
hoc group of environmentalists over a plan to build a Jetport in a
large wetland area located in Morris County, New Jersey. (This
occurred between 1959-1968. Spoiler alert: the environmentalists
won, and the wetlands are now known as the Great Swamp National Wildlife Refuge. )
One thing that jumped out at me was a small comment near the
end of the film. Before suggesting that a jetport should be built, the
PANYNJ commissioned a study of air travel patterns in the region.
Continued on page 33...

Here is an update on the five Dysprosium 2.0 strategies:
1.) Additional resources have been located, but since prices for
About the Author - Dr. Stan Trout has more than
40 years' experience in the permanent magnet and
rare earth industries. Dr. Trout has a B.S. in Physics
from Lafayette College and a Ph.D. in Metallurgy and
Materials Science from the University of Pennsylvania.
Stan is a contributing columnist for Magnetics Business
& Technology magazine. Spontaneous Materials, his
consultancy, provides practical solutions in magnetic
materials, the rare earths, technical training and technical writing. He can be reached at strout@ieee.org.

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