Accession Number : AD0721374

Title :   Mechanical Behavior of Aluminum-Stainless Steel Composites Subjected to Elevated Temperature Exposure.

Descriptive Note : Technical rept.,

Corporate Author : DREXEL UNIV PHILADELPHIA PA DEPT OF METALLURGICAL ENGINEERING

Personal Author(s) : Pattnaik,A. ; Lawley,A.

Report Date : MAR 1971

Pagination or Media Count : 40

Abstract : Room temperature tensile behavior to failure is correlated with associated intereface microstructure, matrix substructure, and fracture morphology in aluminum-stainless steel composites (Vf = 6.5%.19.6%) in the as-pressed condition and after exposure at temperatures of 550C or 625C. Heat-treatment at either temperature does not affect stages I and II of the stress-strain curve but does reduce the ultimate tensile strength; strain to failure is not impared after the 550C heat-treatment but is significantly lower following heat-treatment at 625C. These observations are consistent with the observed fracture morphology of composites and wires pulled to failure after extraction from the composites. A 'corn-cob' structure develops on the wire surface at each temperature; ductile behavior of the wires is confirmed after heat-treatment at 550C but not after heat-treatment at the higher temperatures. Reduction in strength is attributed to the development of a brittle interfacial zone. Composite tensile strengths in the three conditions are in reasonable agreement with rule-of-mixtures predictions using measured strength levels for the extracted wires in the calculation. In each condition, a dislocation cell structure develops in stage III with the cell size relatively independent of distance from the matrix-wire interface; the cell structure is comparable to that formed in unreinforced aluminum at comparable levels of strain. (Author)

Descriptors :   (*COMPOSITE MATERIALS, *ALUMINUM), (*REINFORCING MATERIALS, STAINLESS STEEL), WIRE, MECHANICAL PROPERTIES, HEAT TREATMENT

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE