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Abstract:
Oxidation
of the Ti6Al4V alloy at high temperature is a problem for the sound
products. In order to protect the alloy from oxidation, surface coating
method has been attempted and several coating materials has been
investigated. A zircon coating is applied to the surface of Ti6Al4V
alloy by plasma spray and the effect of coating on the superplasticity
of the alloy as well as the oxidation behavior of the oxidation are
studied. Uniaxial tensile tests are conducted at 800 ℃, 850 ℃ and 900 ℃
with an initial strain rate of 0.000 1 s–1, 0.00 1 s–1, 0.01 s–1 and 0.1
s–1. Studies show that an oxide film is formed on the surface of Ti6Al4V
alloy and no such oxide film is found in the coated specimens. XRD and
EDX analysis indicate that this oxide film mainly consists of TiO2. The
thickness of the oxide film increases with increasing temperature and
exposure time. Studies show that the elongations of the coated specimens
are higher than those of the uncoated ones, while the ultimate strength
and yield strength of the alloy are not changed. The difference in
elongation between the coated and uncoated specimens is influenced by
the temperature and initial strain rate. However, studies also show that
there are some clefts formed on the coating layers at the later stage of
deformation due to the brittle nature of the coating layers.
Key words:
Titanium alloys Zirconia coating High temperature oxidation
resistance Tensile test
CLC No: TG146
教委留学回国启动基金(63009012200402)、北京工业大学青年基金(97009012200401)和国防预研基金(51461070304QT0101)资助项目. Received
20050706, received in revised form 20060225
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