Research On The Thermal Oxidation Behavior Of TC4?TA19 And Ti17 Titanium Alloys

TC4,TA19 and Ti17 titanium alloys are widely used in the industrial field.These three titanium alloys have different degrees of thermal oxidation resistance,when they are used to manufacture all kinds of components and serviced in high temperature oxidation environment for short-term or long-term.The degree of oxidation reaction may have influence on the performance of the alloy.Therefore,the study of thermal oxidation behavior of titanium alloy at different temperature and time can help us to judge whether the performance of titanium alloy meets the required standards.This paper mainly studied the thermal oxidation behavior of TC4,TA19 and Ti17 titanium alloys at high temperature.First,the semi-finished products of the three kinds of alloys were machined into plate samples in accordance with the national standard.When the furnace temperature reaches the predetermined temperature,the three kinds of alloy samples are marked and put into the furnace for heat treatment.Heat treatment temperatures included: 300 ?,400 ?,500 ? and 600 ?,and four soaking times were studied at each temperature:1 h,6 h,24 h and 48 h.When the thermal oxidation experiment is over,the sample is taken out and cooled by air.The color changes of oxidized titanium alloys were recorded by a scanner.The weight gain of three titanium alloys at 600 ? was analyzed by using an electronic balance,and the oxidation kinetics curves within 48 h were described.X-ray diffractometer was used to qualitatively analyze the phase on the surface and the thermal oxidation products on the surface of different alloys were determined.Using scanning electron microscope(SEM),and energy disperse spectroscopy(EDS),the changes of surface microstructure of three alloys were detected before and after the thermal oxidation,and the time and temperature corresponding to the appearance of surface oxide particles were obtained,and then oxide morphologies on the surface of three alloys were summarized.Finally,after grinding off the oxide film,the thickness of oxide layer was analyzed with line scanning in SEM on the cross section of samples.Optical microscopy was used to analyze the microstructures of three titanium alloys before and after thermal oxidation at 600 ?.The types of elements on the surface of the three alloys at 600 ? for different time and the valence states of titanium,oxygen and aluminum after oxidation at600 ? for 24 h and 48 h were studied qualitatively by X-ray photoelectron spectroscopy.The types of oxides on the surface of the alloys were determined according to the valence states and compared with the XRD results.