Precipitation of Secondary Phase and Phase Transformation Behavior of a Solution‐Treated Ti–6Al–4V Alloy during High‐Temperature Aging

Abstract

The precipitation of secondary phase and phase transformation behavior of a solution-treated Ti-6Al-4V alloy during aging heat treatment are investigated. The content, size of the equiaxed α phase, and the thickness of secondary phase are greatly influenced by the aging temperature. With the increased aging temperature, the mean grain size of the equiaxed α phase significantly decreases, whereas the precipitation process of the secondary phase is accelerated. Furthermore, during aging heat treatment, the precipitation and growth of the secondary phase not only destroy the initial lamellar α phase, but also connect with the equiaxed α phase to form a new curved lamellar α phase. In addition, it is found that the α 0 phase is precipitated, and the α 0 !α þ β phase transition occurs with the increased aging temperature.

Hot Processing of Powder Metallurgy and Wrought Ti-6Al-4V Alloy with Large Total Deformation: Physical Modeling and Verification by Rolling

“…Consequently, the b fi a + b transformation had to take place. It can be seen that after the first MaxStrain deformation stage (Figures 7(c), 8(c)), the microstructure had features characteristic for cooling down from the temperature above b-transus [45,46] . The massive a lamellae on the primary b grain boundaries and the colonies of thin plates within them are visible.…”

Effect of Duplex Aging Heat Treatment on the Stress Corrosion Cracking Behavior of Ti-6Al-4V α+β Titanium Alloy in Methanol

“…The aging treatments were done in controlled argon atmosphere oven, in order to prevent the formation of oxides. The first aging stage was done at 600°C for 1 hour with oven cooling, this higher aging temperature was chosen in order to cause a strong decomposition of solution resulting lamellar grains 10 . The second aging stage was done at in a lower temperature of 450°C, for 1 hour, also with oven cooling.…”

Microstructure and Thermal Stability of High‐Temperature Titanium Alloy with Hf Element

“…High-temperature titanium alloys are widely used in aerospace engines and other high-end engineering scenarios because of their excellent performance, such as high toughness, fatigue strength, and creep resistance. [1][2][3][4][5] For a long time, near-α titanium alloys have been developed competitively all over the world. [6] For example, IMI 834 was originally developed by the British, [7] then Ti-1100 was developed in the USA, [8] followed by BT18y in Russia, and Ti-60 in China, [9,10] these alloys have been used up to a maximum service temperature of about 600 °C.…”