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Introduction:
A strategic goal of Marlow Industries, Inc. is to maintain and improve
our leadership in thermoelectric products and materials performance.
This portion of the web site will explore the nature of leadership in
materials performance and its footprint in the products and services we
offer. Thermoelectric technology has stagnated, in a sense, with very
little improvement for nearly 30 years... until recently. One goal of
this section therefore will be to provide you, the visitor to Marlow
Industries via the web, with some insight into the field of materials
science and how it pertains to the development of our products.
Plastic Deformation:
One of the most famous lines
in modern movies is from "The Graduate" written by Buck Henry,
"Plastics", "There is a great future in plastics".
This line conveyed the irony wrapped up in the succeeding generation's
advise. The stagnation in thermoelectrics in each of several 30-50 year
periods in its nearly 200 year life has been immersed in similar
intergenerational irony.
We inherited an approach
that taught that the single crystal thermoelectric materials of
the Bismuth Telluride alloy family were the most efficient materials.
That was true through that era. The reason it was true was because the
material we use is highly anisotropic; "different in different
directions". The material is almost twice as efficient in one
crystallographic direction as it is in the other. You need a single
crystal to get the orientation you need. Unfortunately, a single crystal
of this material is very fragile, and we were caught with a trade-off
between fragility or performance - take your pick.
Marlow Industries and
several of its competitors, independently recognized over the past few
years, that the constraints drawn from these past words of wisdom were
no longer valid.
It is possible to get
high degrees of orientation with grains of our material the size of sand
or smaller, when they are densified properly. Materials composed of fine
grains in this manner are very durable and can exhibit high performance.
Improper densification
results in randomness in orientation and impurities on the surfaces. The
combination of these two phenomena was catastrophic on performance. The
success in avoiding these results took the dedication of several
generations of researchers, but it happened.
As a result many of us
learned, slowly and surely, that orientation could be achieved, and that
the debilitating effect of the surface of the grain could be overcome.
We are today, bringing those results to market.
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MAM:
Micro-Alloyed Material:
MAM is the
acronym in Marlow Industries for our fine grain, high
performance material. We have not measured any material in our
laboratory with higher figure of merit than MAM. We have also
proven the material's mechanical strength. We have tried to
measure all material in production in the world as a basis of
comparison for this statement. Our doors are open. We will
measure any competitor's material we can properly acquire and
report on the results scientifically, as is possible.
Marlow
Industries, has thousands of hours of testing on MAM and is
providing our customers with the details they need to qualify
the devices fabricated from this material. The results when the
day is done are gratifying. This is not to say that introducing
a new material into a market, which has relied on another format
for so long, is trouble free. Believe us it wasn't, but when the
activity settled out, meaning when all of the downstream
processes were optimized and released to production, we have
proven to ourselves that this is the path to the future. We have
high expectations for what we can do next.
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In addition to increased
performance, an additional benefit of MAM is it opens the door for
several innovations in downstream processing and assembly. This
translates into an exciting opportunity to engage our customers early in
the design cycle and explore design formats, and assembly techniques,
which result in new, mutually beneficial cost/performance options.
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