Accession Number : AD0651267

Title :   EFFECT OF TEST BAR DESIGN ON MECHANICAL PROPERTIES IN CAST LEAD-TIN BRONZE.

Descriptive Note : Technical rept.,

Corporate Author : ARMY WEAPONS COMMAND ROCK ISLAND ILL RESEARCH AND ENGINEERING DIV

Personal Author(s) : Wurtz,Wade C.

Report Date : MAR 1967

Pagination or Media Count : 25

Abstract : A study was made of the solidification behavior of lead-tin copper-base alloys, as affected by the dimensional and volume relationships of the mold, in order to assure a design which would produce a sound and representative test bar. Experimental design modifications were made to the Federal Test Method Standard No. 151a vertical full-web test bar mold. Tests were conducted using tin bronzes of Compositions 2, 4, 5, 8, and 12 of Federal Specification QQ-B-1005, and Composition A of Federal Specification QQ-B-726, Manganese Bronze. Optimum mechanical properties were obtained by using a 3/8 inch web for Composition 2, 4, 8, and 12 while a 3/16 inch web showed the best results with Composition 5. A 3 inch high riser with a volume of 27 cubic inches provided the best mechanical properties with Composition 5. The rate of temperature drop in the metal and the sequence in which freezing occurred at different mold locations was obtained by tracing cooling curves with a recording potentiometer connected to thermocouples inserted into mold cavity at these locations. (Author)

Descriptors :   (*BRONZE, MECHANICAL PROPERTIES), (*CASTINGS, BRONZE), LEAD ALLOYS, TIN ALLOYS, FREEZING, TEST METHODS

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE