Science: Robertson-Bonded-Metal

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Out of Mellon Institute of Industrial Research in Pittsburgh last week rolled a strange new material. It looked and felt like a sheet of steel, but its surface did not shine like steel. It was a surface soft as felt. A casual observer would have guessed it was steel covered with felt. Dr. Alden William Coffman would have pointed out that a cross section showed no line of demarcation between felt and steel. Then Dr. Coffman, who developed it, would have explained that it was felt-coated steel, but that the felt was not merely a covering, was an integral part of the substance.

Known as R-B-M (Robertson-Bonded-Metal), the new steel is an amalgamation of three substances. Pure steel is coated with an alloy of tin, lead or zinc. The alloys are then heated to a temperature just beyond the plastic point but below the liquefaction mark. At this temperature felts can be cemented to the alloys. Upon cooling the felt adheres to the steel by means of the adhesive alloy. On the felt may be grafted further coatings—of asbestos, cellulose, imitations of wood, silk, jewels. The new metal may be rolled, drawn, pressed, corrugated. Chief difficulty is in getting exactly the right temperature and pressure to effect the amalgamation.

Dr. Coffman foretold many uses for his felt-steel roofing and sidings for buildings, pipe lining, paneling, fireproofing. When struck the material does not ring like steel, an advantage in a decibel-conscious age (see p. 36).