July 17, 1997 11 a.m. CDT
Check out our highlights page for MSL-1!!
Fire -
either flame or electric - is used to melt metals to form new shapes and
materials. Several MSL-1 experiments were designed to study how to make
those products better, something mankind has done since early humans discovered
that fire softened metals and made them easier to work.
Germany's TEMPUS
electromagnetic furnace for containerless processing (left) completed one
experiment beyond the 20 planned as it gave TV viewers on Earth the occasional
sight of a bouncing ball turning white hot then cooling again. In 197 hours
of experiments, TEMPUS used magnetic fields to position metal samples, about
the size of a gum drop, and radio waves to melt them in 22 experiments.
Observations of how they shook and how far they went below freezing before
freezing (yes, that's right; it's undercooling) will yield basic physical
data that eventually will be used in steel mills and other factories. TEMPUS
provided the first specific heat (amount of heat per unit mass) and thermal
expansion of a new class of glass-like metal alloys. Zirconium was heated
to 2,000 degrees C (3,632 degrees F) and cooled - sometimes to 340 degrees
C (612 degrees F) below freezing - 120 times, something impossible on Earth.
It also provided the first measurements of the viscosity (thickness) of
undercooled palladium-silicon alloys, detailed data on iron-nickel,chromium
(an important commercial metal), and the potential formation of a liquid
magnet with cobalt palladium undercooled by 330 degrees C (594 degrees F).
Japan's Large Isothermal Furnace (LIF) baked metal samples at an even temperature so scientists
can measure the fine details of how metals diffuse or slowly flow into each
other. Gravity's effects disrupts such measurements on Earth. Two experiments
also looked study how metals are formed by sintering, melting and compressing
metal powders. Results will be known when scientists dissect their samples
on Earth. All 25 samples were processed with little difficulty.
Results from the Coarsening in Solid-Liquid Mixtures (CSLM; also
in the glovebox) also will have to wait post-flight analysis of its nine
samples. CSLM is a study of why grains in alloys grow larger at the expense
of smaller grains, thus weakening jet turbine blades and other crucial materials.
Author: Dave Dooling
Curator: Linda Porter
NASA Official: Gregory S.
Wilson