Preparation of heat-resistant aluminum alloy pipe blanks by
multi-layer spray deposition①
multi-layer spray deposition①
(Research Institute for Non-equilibrium Materials Science and Engineering,
Central South University of Technology, Changsha 410083, P.R.China)
Central South University of Technology, Changsha 410083, P.R.China)
Abstract: A heat-resistant aluminum alloy pipe blank with dimensions ofd700/300 mm×1 200 mm was prepared by the multi-layer spray deposition technology. Optical microscopy, X-ray diffractometry and transmission electron microscopy were used to analyze its morphologies and microstructures. The results show that the microstructures of the pipe blank are homogeneous and the precipitates are uniformly-distributedd25~70nm spherical or sphere-like Al12(Fe,V)3Si particles, its mechanical properties at room temperature and 350℃after densification by extrusion areσb=412MPa,δ=7.6% andσb=187MPa,δ=7.6%, respectively. The analyses indicate that the proper match of the motion rates of atomizer and substrate can produce deposited blanks with uniform thickness and relatively high cooling rate.
Key words: heat-resistant aluminum alloy; pipe blanks; spray deposition; rapid solidification