Radio age research, manufacturing, communications, broadcasting, television (1941)

convenient manner by any known method, a means was sought for plating the ahiminum with another metal, to provide an easily solder- able surface and. at the same time, a better means of assuring good electrical contact. But neither can aluminum be directly plated, so an indirect approach was necessary. After some study, our laboratory found a conducting material which could be applied to aluminum as film by means other than plating, and developed a process for apply- ing it and for subsequent plating of the aluminum thus treated. Common starch came to the res- cue as a flu.xing agent for various soldering operations when we found that neither rosin nor zinc chloride, which are the agents most exten- sively used, would do the job in cer- tain applications. Fluxing agents are used to cleanse the surfaces to be soldered, and make the solder alloy with the base metal. Zinc chloride is a pow- erful flux, but tends to cause cor- rosion unless the soldered parts are washed to remove the excess flux after soldering. Rosin, though free of this fault, is not a very active flux, particularly when used with such metals as steel. In certain types of equipment it was found necessary to solder steel parts together, but impossible to wash the parts after the operation. Our laboratory solved the problem with the discovery that levulinic acid, derived from common starch, was a much more active flux than common rosin. It was found that DR. LEOPOLD PESSEL. SPRAYING A WASH ON QUARTZ CRYSTALS TO REMOVE EXCESS SILVER SOLUTION. SILVER IS DEPOSITED ON THE CRYSTALS TO FORM ELECTRODES. this acid, when blended with rosin, could be used in soldering steel parts without the necessity for sub- sequent washing. Process as well as materials prob- lems have yielded to applied science in our laboratory. The problem of how best to deposit silver on quartz crystals to form electrodes, for ex- ample, was one of the serious poten- tial bottlenecks faced by our organ- ization when the war made it neces- sary for us to convert to a mass production industry, almost over- night, what had been only a limited activity in the manufacture of crystals. Although the Rochelle salts meth- od appeared to be the most adapt- able to mass production, the first results with this method were dis- appointing. The method had been applied largely in the past to satis- fying optical requirements, and the technique of operation had been directed to that end. It was found that uniformity of film thickness, directly affecting electrical results, could not be guaranteed, while the adhesion between silver and quartz was poor. A process overcoming these difli- culties and satisfying all require- ments was developed, but not until after we had completed a study of the effect of solution concentra- tions, temperatures, times of im- mersion, rate of flow of solutions over the crystal face, and the role played by the compound, silver tartrate. As has already been indicated, not all of our materials problems have resulted from shortages. New requirements, rendering materials formerly used unsatisfactory, have played their part. This was true in the case of petroleum asphalt as a substance for impregnating and potting transformers. Although petroleum asphalt re- mained plentiful, it did not inher- ently possess the properties re- quired to meet more exacting test specifications as it became neces- sary for transformers to operate under more severe conditions. In this instance our laboratory found means of modifying the substance by blending it with other materials. Our borrowings from the paint industry involve the use of a black oxide of iron, specifically developed 26 RADIO AGE] as a pigment, as the essential ma- terial in the manufacture of cores used in controlling the effective permeability of magnetic circuits. Such satisfactory solutions of materials and process problems as those enumerated have been pos- sible at RCA Victor because of the fact that our organization, with its background of experience in the various kinds and applications of engineering and science, was from the beginning in a relatively fortu- nate position to meet the challenge of wartime requirements. Some manufacturers were not so well prepared. Actually, wartime manufacturing conditions have, in some instances, only emphasized fundamental weaknesses that were present in pre-war days, increasing costs and constituting a self-im- posed break on maximum progress. However, as more and more rigid specifications have been introduced and the number of new or substi- tute materials increased, even man- ufacturers lacking previous experi- ence in the scientific solution of such problems have begun to seek out the special training and experi- ence most applicable to help them meet their emergencies. To make the wisest use of the chemical sciences, it is essential to know the scope and purpose of the various specialized branches. Gone are the days when the individual chemist might be expected to give an authoritative opinion on such widely different subjects as metals and alloys, dyes, plastics, and tex- tiles. Partly because of the ever- expanding horizon of the chemical sciences, and partly because of the number and complexity of raw ma- terials and process requirements entering modern manufacturing in- dustries, it has been almost imper- ative for the individual chemist to undertake some specialty. While it may rarely be either ad- visable or necessary to utilize all the branches of the chemical sci- ences in a specified industry, the bringing together of the needed specializations to form a strong, woll-organized unit dedicated to the scientific solution of materials and process problems can do much to reduce costs and to keep products ahead of the field.