Because the microstructure of titanium alloy is easily affected by processing variables, microstructure control is the foundation of successful processing of titanium alloy, so one of the main purposes of forging is to obtain the comprehensive mechanical properties of titanium material. Titanium and titanium alloy forging according to the heating temperature can be divided into: lower than the beta transformation point (alpha beta) forging and higher than the beta transformation point of beta forging. The higher the processing temperature in the (αβ) region, the more β phase can be transformed upon cooling. Section size requirements are important, the number of machining operations is multiple, regular forging requires two or three operations, and isothermal forging requires only one. The effect of (αβ) forging on the microstructure is cumulative, especially the change in α morphology, so that each successful (αβ) machining operation produces a change in the structure obtained by the previous operation. The alpha phase transformation in beta alloys during forging is not prevalent, so typical forging of beta alloys is above the beta transition point.

Beta forging is a forging technique in which most or all of the forging process is completed at a temperature above the beta transformation point. The microstructure of the β-forging alloy is a transformed β or acicular microstructure. Although the yield strength after beta forging is generally not as high as that of (αβ) forging, the notched tensile strength and fracture toughness are relatively high. Therefore, beta forging is used to improve high temperature performance and fracture related properties such as creep resistance, fracture toughness, fatigue crack growth resistance. In fact, a number of recently developed alpha alloys are designed for beta forging to achieve the desired mechanical properties. Compared to (αβ) forging, β forging typically has a loss in strength and ductility. The effect of beta forging processing on the microstructure is not cumulative; each processing above the beta transformation point-cooling and re-heating cycle, the effect of the previous processing is at least partially lost, because heating above the beta transformation point of the alloy causes recrystallization. B forging in the forging unit pressure has a significant reduction and reduce the tendency to crack, but must strictly control the forging processing conditions, in order to avoid uneven processing, rapid growth of grain or poor processing organization, all conditions may cause forgings or the same forgings The mechanical properties between batches and batches are greatly changed.

Effect of strain rate: Titanium alloys are highly strain rate sensitive in forging processing. Strain rate sensitivity at forging temperature is higher for beta and near-beta titanium alloys. However, the strain rate sensitivity of the α and α-β alloys is relatively small. In titanium alloy regular forging, intermediate strain rates are usually used in order to obtain the best possible deformation. With fast strain rate forging techniques, such as hammer or mechanical press forging, the heat of deformation during forging becomes important. Due to the relatively poor thermal conductivity of titanium alloy, temperature imbalance may occur, so in the rapid forging of titanium alloy, the metal temperature should often be adjusted to consider the temperature rise of the forging process, or control the forging process to reduce the temperature rise.