Metallurgy; an introduction to the study of physical metallurgy . oing soHdification in the usualmanner, but afterwards—on cooling to a lower temperature—again becoming liquid, and only then undergoing final sohdifica-tion at a still lower temperature. Such behaviour can, ofcourse, only be explained by the occurrence of a chemicalreaction as the result of which the crystals of a sohd solutionare transformed into a compound—or a solution of a compoundin an excess of one of its constituents—^which is more fusiblethan the original sohd solution, with the result that the forma- 150 STUDY OF PHYSIC
Metallurgy; an introduction to the study of physical metallurgy . oing soHdification in the usualmanner, but afterwards—on cooling to a lower temperature—again becoming liquid, and only then undergoing final sohdifica-tion at a still lower temperature. Such behaviour can, ofcourse, only be explained by the occurrence of a chemicalreaction as the result of which the crystals of a sohd solutionare transformed into a compound—or a solution of a compoundin an excess of one of its constituents—^which is more fusiblethan the original sohd solution, with the result that the forma- 150 STUDY OF PHYSICAL METALLURGY tion of the compound on cooling through a critical temperatureis accompanied by the fusion of the alloy which had justpreviously solidified. In the preceding sections the constitution and structure oftypical members of the two binary series—zinc-copper andtin-copper—have been very briefly discussed. A very largenumber of important alloys, however, although closely relatedto these two series, are essentially ternary alloys in which both. Fig. 61.—Diagram of the ConBtitution of the ternary alloys of Tin, Zincand Copper, rich in Copper. zinc and tin are present. In view of the complexity of boththe two binary systems, it might be anticipated that the ternaryequiUbrium would be excessively comphcated. Actually thesystematic investigation of these ternary alloys has only beenundertaken quite recently by Hoyt {), but although thatauthor has obtained interesting and valuable data, it cannotbe considered that these alloys have been fully explored as yet,As far as it goes, Hoyts ternary diagram is reproduced inFig. 61. The diagram relates only to the corner of the ternarytriangle representing the alloys rich in copper ; the figure shows TYPICAL ALLOY SYSTEMS 151 the binary diagrams of the zinc-copper and the tin-coppersystems folded down to either side of the triangle, while themanner in which the various regions of the binary diagramsare connected in the ter
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectmetals, bookyear1922
