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In this study, an Al-Y coating was applied to enhance the property of oxidation resistance on the surface of γ-TiAl alloys by rf magnetron sputtering. The isothermal oxidation tests were investigated at 900 °C for 100 h. The coating characteristics and microstructure of coating after isothermal oxidation were inspected by XRD and SEM methods respectively, and coating bonding strength was investigated by scratch tester. Results show that Al 2 O 3 and Y 2 O 3 were produced on the surface of γ-TiAl alloys to enhance oxidation resistance during the isothermal oxidation test. Diffusion layer with rich element of Al provides abundant Al to surface for formation of a continuous Al 2 O 3 layer which increases oxidation resistance effectively. Oxides of YAlO 3 and YAG were formed during the oxidation tests, which were beneficial for the strength, hardness and fracture toughness of crystal grain of Al 2 O 3. Furthermore, Element of Ti diffused into surface from substrate was restrained by Al because of the formation of TiAl 3 and TiAl, which avoid the layer-broken by titanium oxides with porous structure

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The nature and extent of molecular "ordering" in alternate-layer Langmuir-Blodgett films of 4-nheptadecylamido-4,-nitrostilbene/stearic acid and a functionalized diarylalkyne (JTll) have been elucidated using infrared linear dichroism. Comparison of intensity ratios of certain infrared bands in the attenuated total reflection and the reflection-absorption spectra has been used to determine the details of the molecular geometrical arrangement from the resulting directions of the selected transition moments. This information, along with spectra of hydrogen-bonded stilbene and stearic acid C=0 groups, leads to a predicted "structure" which is consistent with the observation of a rather modest nonlinear optical coefficient. This should lead to an improved design strategy for the successful production of organic nonlinear optical devices.hydrogen bonding plays an important role in the separation and ordering of the active molecules involved in second

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