To meet the demands of missile makers, U.S. scientists have worked for years on metals that can resist the high temperatures generated by supersonic speeds. One such metal is molybdenum, which melts at 4748° F., v. about 3000° F. in commonly used alloys. But making molybdenum castings was long impossible; its melting point is so high that it destroyed the crucible holding it. Last week the U.S. Bureau of Mines announced "a major metallurgical breakthrough"; it had succeeded in making molybdenum castings.
Metallurgists melted a 30-lb. piece of molybdenum with a high-density electric arc in a copper-lined, water-cooled crucible. The...
To continue reading:
or
Log-In
