Experimental Study And Theory Analysis Of Endurance Life For Crystallizing Turbine Blade

High-pressure turbine blades which are used for some advanced grind type of engine at present are made up of a directionally crystal nickel-base high-temperature alloy. We select material from representational part of turbine blade in order to increase the reliability of design parameters and design method for endurance life of turbine blade,.We perform the tensile test in short-term at room temperature, 760 centi-degree and 980 centi-degree with MTS810 hydraulic pressure servo material test machine. The stress-strain curves of the corresponding temperature are received. Mechanical properties of material are compared with that of standard specimens.Endurance experiments are done at 980 centi-degree. Test data are very discrete. There are actual specimens of eccentricity because of the control problem of processing accuracy. So it is necessary that finite element stress analyses about effects of eccentricity are performed with ANSYS considering the creep properties of high-temperature materials. Meanwhile, we need to obtain Norton regression of creep data with different stress at 980 centi-degree because the creep laws are determined with the input parameters in ANSYS. But the direct Norton regressions can not be carried out since we have only the creep data under a stress result at 980 centi-degree.In this thesis, firstly, we apply MATLAB to obtain Norton regression of 950 centi-degree. Secondly, we adopt non-linear least square method to get parameters of θ -Project Concept with FORTRAN programming and get creep data at 980 centi-degree with different stresses. Thirdly, the creep constitutive relations obtained by the above two type of Norton regression are introduced in ANSYS respectively; finite element stress analyses about effects of eccentricity are performed with application of Norton creep law. It is concluded that we should use the above second Norton regression. Computed endurance life is compared with experimental endurance life in order to confirm validity of experimental results.