Study On Mechanical Properties Of Panxi Sponge Titanium Used In TA15 Titanium Alloy

Titanium and titanium alloys have been widely used in aerospace,chemical and civil applications for their excellent performance.As the main raw material for the production of titanium alloy,titanium sponge plays an important role in the development of titanium industry.Aiming at TA15 titanium alloy with medium strength and near alpha type widely used in the field of aerospace,this paper studied the melting process and mechanical properties of TA15 titanium alloy prepared based on panxi titanium sponge,which laid a theoretical foundation for further developing panxi titanium resources utilization and popularizing engineering application.In this paper,the influence of melting process parameters on the quality of alloy ingots was analyzed,and the optimal melting process parameters were obtained by finite element simulation.The MeltFlow-VAR finite element software was used to simulate the influence of melting speed and steady arc current on the alloy element distribution and composition uniformity in vacuum consumable smelting,and the best melting parameters were obtained.The Panxi sponge titanium raw materials were analyzed.The influence of the content of impurity elements on the overall quality of the finished ingot.Using the TA15 titanium alloy bar(?300mm)produced by WST.Inc.,the mechanical tests at different temperatures were carried out by electronic tensile testing machine,and the changes of tensile strength and yield strength at different temperatures were analyzed.The impact test was used to obtain different Impact toughness and plane fracture toughness at temperature;the fatigue ultimate strength of the alloy under different conditions was obtained by high cycle fatigue test;the tensile/impact/fatigue fracture morphology and the nearby microstructure were analyzed by optical microscopy.appearance.Studies have shown that by optimizing and selecting the parameters of consumable smelting process,it is possible to ensure the composition uniformity and impurity content control of the ingot.The magnitude of the steady arc current determines the alloying effect of the ingot,and the melting speed affects the bath depth and temperature field distribution.The temperature increases from-60°C to 900°C,the alloy strength and elastic modulus values decrease with increasing temperature,whereas plasticity increases.In addition,the tensile properties of the material vary at different temperatures.Through the high temperature tensile fracture analysis of the alloy,it can be inferred that the isothermal temperature may appear at 600~700°C;as the temperature increases,the impact energy increases gradually,but the impact performance varies in different temperature ranges;room temperature S-N curve(stress ratio R=0.06)does not show a fatigue limit in the horizontal line.The calculated fatigue limit is 525.7 MPa and the coefficient of variation is 0.026(N=10~7).