A Fundamental approach to the Study & Control of Failures due to Liquid or a Brittle Phase Enveloping Grains

Abstract

The concept that the microstructure is the resultant spatial distribution between phases and grain interfaces is developed on the fundamental law of the triangle of forces. Microscopical evidence of this is presented by a study of the intergranular penetration of lead, bismuth, phosphorous and others in copper and brass showing also the effect of alloying additions on the angle of pene-tration or the `dihedral angle'. This concept of the dihedral angle is adapted to formulate a theory of the mechanism of intergranular failures. It has also been shown how by a proper and judicious addition of an alloying element the interpenetration of a liquid or a brittle phase could be avoided thus preventing an inter-granular failure. The importance of this approach in the study and control of such intergranular failures as that of boiler plates, brasses, stainless steels & such others is stressed.