Krell metal
I was eight when I first saw the movie Forbidden Planet (1956, Fred M. Wilcox, Director). The plot revolves around an expedition to Altair IV, the fourth planet of the star Altair, a planet once populated by the Krell. The Krell were long extinct, but they left behind many artifacts, including many made from Krell Metal, a nearly indestructible alloy. Krell Metal is not the only fictional, indestructible alloy. Adamantium, a name likely derived from the word adamantine with an -ium ending for chemical affect, has similar properties.
Many years later, when I was at Syracuse University, one of my fellow graduate students synthesized a close cousin to Krell Metal, the intermetallic compound HfPt3. HfPt3 has an enthalpy of formation (∆Hf) of -132 kcal/mole and a melting point of about 2400 K (3850 °F). A closely related compound, ZrPt3, has an enthalpy of formation (∆Hf) of -124 kcal/mole and the same melting point. I've measured the Rockwell-C hardness of HfPt3 to be 65.2. For comparison, hard chrome coatings have a hardness of 60 on the Rockwell-C scale. HfPt3 was so hard, standard metallography techniques could not be used. We needed to treat this metal as if it were a ceramic.
Robbie the Robot was my favorite character in Forbidden_Planet, but in later years I became somewhat partial to Anne Francis. The movie had the first electronic music soundtrack, produced by Louis and Bebe Barron, but the musician's union prevented the Barron's from being credited as "composers." They were credited with "electronic tonalities," instead. Forbidden Planet has been compared to Shakespeare's The Tempest, with the part of Caliban played by Robbie the Robot.
References.
1. V. Srikrishnan and P.J. Ficalora, Metallurgical Transactions 6A (1975), pp. 2095ff.
2. Forbidden Planet on the Internet Movie Database (imdb.com)