skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Microstructural evolution of 6063 aluminum during friction-stir welding

Abstract

The microstructural distribution associated with a hardness profile in a friction-stir-welded, age-hardenable 6063 aluminum alloy has been characterized by transmission electron microscopy (TEM) and orientation imaging microscopy (OIM). The friction-stir process produces a softened region in the 6063 Al weld. Frictional heating and plastic flow during friction-stir welding create fine recrystallized grains in the weld zone and recovered grains in the thermomechanically affected zone. The hardness profile depends greatly on the precipitate distribution and only slightly on the grain size. The softened region is characterized by dissolution and growth of the precipitates during the welding. Simulated weld thermal cycles with different peak temperatures have shown that the precipitates are dissolved at temperatures higher than 675 K and that the density of the strengthening precipitate was reduced by thermal cycles lower than 675 K. A comparison between the thermal cycles and isothermal aging has suggested precipitation sequences in the softened region during friction-stir welding.

Authors:
;  [1];  [2];  [3]
  1. Tohoku Univ., Sendai (Japan). Dept. of Materials Processing
  2. Showa Aluminum Corp., Oyama City, Tochigi (Japan)
  3. Showa Aluminum Corp., Sakai, Osaka (Japan)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
684460
Resource Type:
Journal Article
Journal Name:
Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science
Additional Journal Information:
Journal Volume: 30; Journal Issue: 9; Other Information: PBD: Sep 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; MICROSTRUCTURE; FRICTION WELDING; ALUMINIUM BASE ALLOYS; MICROSCOPY; HARDNESS; PRECIPITATION; SIMULATION; CORRELATIONS

Citation Formats

Sato, Y.S., Kokawa, Hiroyuki, Enomoto, Masatoshi, and Jogan, Shigetoshi. Microstructural evolution of 6063 aluminum during friction-stir welding. United States: N. p., 1999. Web. doi:10.1007/s11661-999-0251-1.
Sato, Y.S., Kokawa, Hiroyuki, Enomoto, Masatoshi, & Jogan, Shigetoshi. Microstructural evolution of 6063 aluminum during friction-stir welding. United States. doi:10.1007/s11661-999-0251-1.
Sato, Y.S., Kokawa, Hiroyuki, Enomoto, Masatoshi, and Jogan, Shigetoshi. Wed . "Microstructural evolution of 6063 aluminum during friction-stir welding". United States. doi:10.1007/s11661-999-0251-1.
@article{osti_684460,
title = {Microstructural evolution of 6063 aluminum during friction-stir welding},
author = {Sato, Y.S. and Kokawa, Hiroyuki and Enomoto, Masatoshi and Jogan, Shigetoshi},
abstractNote = {The microstructural distribution associated with a hardness profile in a friction-stir-welded, age-hardenable 6063 aluminum alloy has been characterized by transmission electron microscopy (TEM) and orientation imaging microscopy (OIM). The friction-stir process produces a softened region in the 6063 Al weld. Frictional heating and plastic flow during friction-stir welding create fine recrystallized grains in the weld zone and recovered grains in the thermomechanically affected zone. The hardness profile depends greatly on the precipitate distribution and only slightly on the grain size. The softened region is characterized by dissolution and growth of the precipitates during the welding. Simulated weld thermal cycles with different peak temperatures have shown that the precipitates are dissolved at temperatures higher than 675 K and that the density of the strengthening precipitate was reduced by thermal cycles lower than 675 K. A comparison between the thermal cycles and isothermal aging has suggested precipitation sequences in the softened region during friction-stir welding.},
doi = {10.1007/s11661-999-0251-1},
journal = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science},
number = 9,
volume = 30,
place = {United States},
year = {1999},
month = {9}
}