The cyclic oxidation behavior of as-forged Ni60 Ti alloy was investigated at 750

8

50 ℃in air environment.The cross-sectional morphologies and phase constituent of the alloy were observed by optical microscope（OM）

X-ray diffractometry（XRD）

scanning electron microscopy（SEM）and energy dispersive spectroscopy（EDS）.The results reveal that with increasing in temperature

oxidation rate and weight-increment are increased.At the early stage of the cyclic oxidation

values of reaction order（n）are less than 2.At the late stage

the values of nat 750℃and 800℃are more than 2

while it is 1.927 at 850℃as a result of oxidation layer cracking and spalling.With temperature and duration increase

a four-layered structure oxidation layer is composed as follows from surface to inner layer:pure TiO

2

rutile

a layer of mixture of TiO

2

and NiTiO

3

a layer of mixture of TiO

2

NiTiO

3

and Ni

Ni

3

Ti layer.