Relaxation of residual stresses in
20%SiCw/6061Al composite
as-extruded at high temperature
20%SiCw/6061Al composite
as-extruded at high temperature
(1. Key Laboratory for High Temperature Materials and Tests of Ministry of Education,
Shanghai Jiaotong University, Shanghai 200030, P.R.China；
2. School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 15000, P.R.China)
Shanghai Jiaotong University, Shanghai 200030, P.R.China；
2. School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 15000, P.R.China)
Abstract: The residual stress in a 20%SiCw/6061Al composite as-extruded was investigated by using X-ray stress measurement method. It was found that, high residual stress existed in the composite and residual stress distribution in each direction are not uniform. Relaxation process of residual stress in the composite was dynamically measured during annealing at high temperature. It is verified that the relaxation of residual stress obeys the power law at high temperature. With the creep mechanism, the relaxation behavior of residual stresses at high temperature was analyzed. The results show that, the stress exponent and activation energy for stress relaxation of the composite are obviously higher than those of the matrix alloy.
Key words: SiCwhisker; Al-matrix composite; residual stress; stress relaxation; X-ray diffraction