New Concepts for the Enhancement of High Strength Aluminum Alloy Properties.

Abstract

The precipitation processes in aluminum alloys are well understood and the identification and analysis of those precipitates primarily responsible for the strengthening effects during precipitation heat treatment is reasonably complete. Less well understood, however, are the roles played by the minor alloying elements involved in the formation of metalloids, dispersoids, and insolubles which are important in controlling, among other things, fineness of grain structure, and the formation of precipitate free zones around grain boundaries. Previously, the study of most of these compounds has been necessarily performed through in situ methods, although anodic dissolution of aluminum alloys in strong acids, or simple dissolution in solutions of iodated methanol have been tried. In addition, extraction-replica techniques have been used to produce small samples of extracted phases for electron microscopy. While a great variety of both chemical and electrochemical methods have been developed for the extraction of secondary phases from steels and nickel-base alloys, until recently, no equivalent anodic dissolution techniques using a relatively inactive electrolyte have been available for aluminum alloys. It has lately been found, however, that methanolic solutions of benzoic acid, oxine and chloroform can be used to selectively remove the aluminum alloy matrix by galvanostatic anodic dissolution, while leaving second phase particles intact.

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1978
Accession Number
ADA055840

Entities

People

  • Franklin H. Cocks
  • George W. Pearsall
  • Marion L. Shepard

Organizations

  • Duke University

Tags

DTIC Thesaurus Topics

  • Alcohols
  • Alloys
  • Aluminum
  • Aluminum Alloys
  • Benzoic Acids
  • Electron Microscopy
  • Elements
  • Extraction
  • Grain Boundaries
  • Heat Treatment
  • Methanols
  • Microscopy
  • Precipitates
  • Precipitation

Fields of Study

  • Materials science

Readers

  • Analytical Chemistry
  • Powder metallurgy of Titanium alloys.

Technology Areas

  • Microelectronics