The growing interest in special acid-resisting alloys and the many uses found for them have stimulated both the search for efficient materials of this nature and the study of the underlying causes of their inertness. Previous studies at the University of Illinois have shown that the almost perfect insolubility of certain alloys in nitric and other acids seems to be conditioned upon a proper mixture of chromium, copper, and nickel, together with smaller quantities of such added metals as tungsten or molybdenum.
As a result of further studies, methods have been developed for making castings of alloys of chromium, copper, and nickel. Twentyone binary and thirty ternary alloys have been prepared, and physical and chemical tests have been made to determine the properties of the various alloys. More :than 3oo corrosion tests have been made to measure the effects of acids upon metals. In general, the results indicate that certain of the alloys of chromium, copper, and nickel give promise of becoming of great commercial importance not only in the construction of laboratory apparatus, but also in manufacturing β’ and chemical processes in which the handling of acids is involved.
Copies of Bulletin 93 containing the results of these tests may be obtained gratis from C. R. Richards, Director of the Engineering Experiment Station, Urbana, Ill.