Accession Number : AD0672751

Title :   THE EFFECT OF SMALL ADDITIONS OF SILVER ON THE MECHANICAL PROPERTIES OF ALUMINUM CASTING ALLOYS.

Descriptive Note : Technical rept.,

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

Personal Author(s) : Miclot,R. B.

Report Date : MAY 1968

Pagination or Media Count : 30

Abstract : The report presents significant test results showing that 0.3% silver additions to melts of certain aluminum casting alloys, 40E and Precedent 71A, increase the yield and tensile strengths without large loss of ductility. Yield strength improves 80% and tensile strength 45% in test-size castings of silver treated 40E alloy, after solution-precipitation treatment; yield and tensile strengths increase more than 13% each, in machined specimens from end-chilled plates. A one week delay between solution treatment and artificial aging of the standard 40E alloy improves the yield and tensile strengths more than 30% each, but no additional improvement occurs in the silver-treated alloy. After artificial aging only, test-size castings from the silver treated alloy increase more than 25% in yield and 10% in tensile strength; machined specimens from plates improve more than 15% in yield and 5% in tensile strength. Only marginal gain in yield strength occurs after natural aging for 40 days. Remelting of the alloy does not destroy the beneficial effects of silver additions. Silver improves the yield strength 5 to 10% in Precedent 71A alloy after solution-precipitation treatment. (Author)

Descriptors :   (*ALUMINUM ALLOYS, MECHANICAL PROPERTIES), DISPERSION HARDENING, SILVER, CASTING ALLOYS, CHEMICAL ANALYSIS, TENSILE PROPERTIES, YIELD POINT, HARDNESS

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE