Complete annealing of titanium and titanium plates

Complete annealing process , titanium and titanium alloys fully annealed purpose is to obtain a stable , good plasticity , or the overall performance corresponds to a certain microstructure . In this process, the main recrystallization , also known as the recrystallization annealing . In addition , there are also a phase and β phase composition, morphology and changes in the number . A majority and a + β titanium alloy is in the fully annealed condition to use. A two-phase titanium alloy whole area is very small, full annealing process occurs mainly recrystallization . Annealing temperature generally choose a + β / β transformation point 120 ~ 200 ℃. Overheating will cause unwanted oxidation and grain growth , incomplete recrystallization temperature is too low . Cooling rate has little effect on microstructure and mechanical properties of these alloys , the general air cooling.

Near a titanium and titanium alloys in a + β recrystallization annealing in addition , there is a phase and β phase changes in the composition, quantity and morphology to determine the annealing process is more complicated . Delivery status for metallurgical plant , the main requirements of stability and plasticity have good organization medical titanium plate. Annealing temperature generally choose a + β / β transformation point 120 ~ 200 ℃, cooling method also uses air cooling. But for the ultimate use of the product before annealing , the annealing process must be based on the impact on the microstructure and mechanical properties determined by experiment .

As metastable β -type titanium alloy , which is fully annealed solution treatment . Metallurgical plant manufactured before the annealing temperature is generally selected a + β / β phase transformation point 80 ~ 100 ℃. Within the recommended range of fully annealing process , the specific process should be determined by test basis processing history , the actual chemical composition, as well as equipment used in the material. In order to avoid unnecessary oxidation of the selection process should meet the performance requirements under the premise of using the lowest temperature and shortest time .

In recent years there has been β annealing process. a titanium alloy and a + β titanium alloys in air-cooled heat after β -phase region , the precipitation of coarse grains β needle ( or flake ) a. This organization corresponds to a high fracture toughness, creep resistance and notch sensitivity , but the plastic section shrinkage and other indicators declined . In the case of this performance can be emphasized as appropriate .
Moreover , for some alloys, when it is desired to improve the performance stability at the working temperature for a long time , are often higher than the temperature used in the second annealing temperature tittanium bar, or other treatment such as TC9 and tc6 alloys.