642 CREATIVE CHEMISTRY metals, produces pyrophoric alloys for pocket lighters and toys, is a powerful reducing agent and can be produced at a relatively low cost from the available abundant raw materials. Cesium and rubidium are used in photo-electric cells. Present research indicates that cesium will be used to produce lamps of far greater efficiency than any known today. Metallic tantalum serves as a cheap substitute for platinum in spinnerets for rayon manufacture. Columbium is a beautiful metal with a promising future as an addition to certain alloy steels. Though many other metals have important special uses that are of benefit to humanity, space will not permit a discussion of them. Not half of the metals have come into common use; there is still plenty of room for the expansion of the science of metallurgy. Who will be the first to discover practical uses for germanium, terbium, indium, thallium, neodymium, lanthanum, samarium, or scandium? An automobile resembling a 1943 model would have weighed three times as much if it had been manufactured out of the lightest materials of equal strength known forty years ago. Some of the Newer Methods of Handling Metals Vastly Extend Their Usefulness. Fabrics, glass, or china may be thinly coated with gold at low cost, so that gold cloth or gold dinner services are within the range of almost any family. Metals may be drawn to fibers of a fineness smaller than any other fiber. Platinum fibers one ten-thousandth of an inch in diameter are replacing spider-web filaments as crosshairs of surveying telescope sights. Textiles may be woven from metallic fibers, and cotton and other fibers may be metalized by coating them with metals. Stainless steel and chromium may be obtained in highly polished, extremely thin sheets that make possible metallic finishes for building purposes at very low cost. STUDY QUESTIONS 1. Which of the metals were known in ancient times? Why were these metals, rather than others, known then? 2. Discuss the operations of metallurgy. 3. What is steel? Discuss the different kinds of steel and the processes used in their manufacture. 4. Discuss corrosion as to (o) what it is, (b) how it is caused, and (c) methods of prevention. 5. Write all you can on the subject of aluminum.
METALLURGY 643 6. List ten metals and mention at least one important use of each. 7. What are the reducing agents most commonly used in metallurgical operations? 8. Aluminum is a more abundant element than iron. How, then, do you account for the fact that aluminum is so much more costly than iron? 9. What are the most useful properties of tungsten? 10. Name a few metals added to steel to give such desirable properties as hardness, resistance to corrosion, etc. IL Under what conditions will iron and steel corrode most readily? 12. Why does aluminum not corrode readily?