I&EC TRENDS TODAY “Corrosion engineers aren’t very creative.” In making this assessment o f his fellows, Dr. E. A. Phelps of U . S. Steel noted that there has been little substantial change in the methodology of anticorrosion protection for many years despite the rapid advances made in chemical analysis and protection systems available to the corrosion engineer. H e sees some justijication for this, however, in the high stakes usually involved. Most projects involve too much money to warrant anything but tried and accepted design methods. The natural result is a well developed reluctance to venture f a r afield into the realm of innovation. A t the same time, most corrosion engineers are convinced that many things could be done to advance the art and science of anticorrosion protection, i f only the basic scientist would transcribe his results into more practical form. The scientist believes that transcribing is the engineer’s business, but neither seems eager to get involved in it. Both are waiting for a third party to emerge andJill the chasm that exists between them. The corrosion dialog between scientists and engineers, sponsored by the National Bureau of Standards, was aimed at bringing the t u o groups together, but only demonstrated the dzflerences that exist. The net result may be closer cooperation but, i f it is to occur without a third party, it is probably quite f a r of. Flame fusion of Tenon to metallic substrates causes less alteration of mechanical properties than the conuentional oven method. Tests conducted by the Naval Iiesearch Laboratory on magnesium and aluminum alloys indicate that a high temperatureflame or some other concentrated source of heat permits good bonding in such a short time that there is only a slight heating of the bulk metal. In the tests the fusion time was short enough to avoid even approaching the decomposition temperature of the coating. Although Tejon was selected because of its association with the thermal fusion process and not because of its corrosion resistance, the tests have prompted further investigation of Tejon films as an anticorrosion protective. The Teflon-coated alloys were found to be the most resistant yet for immersion in 3% brines. Ultrasonic encapsulation of metal inserts in plastics has been successfulZy demon-
strated as a production technique by Branson Instruments, Inc., of Danbury, Conn. Branson believes that the new method will replace the conventional method of molding the plastic material around the metal. The new technique employs sound waves generated at ultrasonic frequencies. The waves are transmitted into the plastic material and travel through it to the junction of plastic and insert. A t the metal-plastic junction, enough sound energy is released as heat to briefly melt the plastic, thus allowing the insert to be introduced. Ultrasonic exposure time is usually less than a second, but during that time the plastic re-forms around knurls, flutes, undercuts, and threads. The encapsulation can be done automatically as a postmolding operation in an assembly line. In addition to the labor savings, less expensive inserts may be used because of the elimination of close tolerancespreviously required. A half-life nomograph for organic peroxides has been designed by the Lucidol diviY Tiernan, Inc., for chemists and engineers involved in monomerpolymsion of Wallace i erization. Its main value is seen to be as an aid in selecting the proper initiator for the operating conditions set. Nomograph variables are the peroxide (20 diyerent ones are included), the ofierating temperature, and the peroxide half-life. Copies can be obtained on request to Lucidol in Bufalo, N . Y . VOL 58
NO. 5
MAY 1966
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