Heat treatment of titanium alloys produced by powder metallurgy

In this thesis, the production and characterization of novel binary and triple titanium alloys for aviation and automobile applications were carried out. In this thesis, binary and triple beta titanium alloys and metastable-beta titanium alloys with low modulus of elasticity and metastable beta titanium alloys that can be precipitation hardening heat treated were produced. Binary and triple titanium alloys were produced by traditional powder metallurgy (presssintering) method. In this thesis, alloy powders were prepared by mechanical alloying (ball mill) method. Then, the green specimens were produced by hydraulic pressing. Then, the green samples were sintered at 1200 °C temperature for 1 hour. Finally, quenching (fast cooling) and aging (precipitation hardening) heat treatments were applied to the sintered titanium alloy samples. The sintered titanium alloy samples were put into solution (austenitization) for 1 hour at 900 °C temperature and then quenching was applied. Then, the quenched titanium alloy samples were aged between 400-520 °C for 1 hour. The effects of various alloying elements added to titanium on the properties of the titanium alloy were investigated The microstructure of the produced binary and triple titanium alloys was investigated using destructive (wear test,hardness test) and non-destructive (ultrasonic testing, eddy current test) methods. Additionally,the electrochemical corrosion behaviour of the titanium alloys was investigated in NaCl solution by using open circuit potential, Tafel and electrochemical impedance spectroscopy tests.