What are the forging methods of titanium materials?

- Nov 13, 2018-

What are the forging methods of titanium materials?

Forging  is a method of forming a mechanical part, a workpiece, a tool or a  blank by applying an external force to a titanium billet (excluding a  sheet) to cause plastic deformation, change in size, shape, and  performance. In  addition, depending on the way the slider moves and the vertical and  horizontal movement of the slider (for forging of the elongated part,  lubrication cooling and part forging of high-speed production), the  compensation device can increase the movement in other directions. Different  methods are used, the required forging force, process, material  utilization, production, dimensional tolerance and lubrication cooling  method are different. These factors are also factors that affect the  level of automation.


According  to the movement mode of the blank, the forging can be divided into free  forging, upsetting, extrusion, die forging, closed die forging, and  closed upsetting. Closed die forging and closed upset forging have high material utilization due to the absence of flash. Finishing of complex forgings is possible with one or several processes. Since there is no flash, the area of force applied to the forging is reduced and the required load is also reduced. However,  care should be taken not to completely limit the blank. To this end,  the volume of the blank is strictly controlled, the relative position of  the forging die is controlled, and the forging is measured to reduce  the wear of the forging die.

According  to the movement mode of the forging die, forging can be divided into  pendulum, pendulum swivel, roll forging, cross wedge rolling, boring  ring and cross rolling. Swing, swivel and shackle can also be used for precision forging. In  order to improve the utilization of materials, roll forging and cross  rolling can be used as a front-end process for slender materials. The  same rotary forging as free forging is also partially formed, which has  the advantage that it can be formed in the case of a smaller forging  force than the forging size. This  type of forging, including free forging, expands from the vicinity of  the mold surface to the free surface during processing. Therefore, it is  difficult to ensure accuracy. Therefore, the movement direction of the  forging die and the swaging process can be controlled by computer. The  forging force obtains products with complex shapes and high precision,  such as forgings such as steam turbine blades with large variety and  large size.

In  order to achieve high accuracy, care should be taken to prevent  overload at the bottom dead center, control speed and mold position. Because these will have an impact on forging tolerances, shape accuracy and forging die life. In  addition, in order to maintain accuracy, you should also pay attention  to adjust the slider rail clearance, ensure the stiffness, adjust the  bottom dead center and use the auxiliary transmission and other  measures.

Titanium  forging materials are mainly pure titanium and titanium alloys of  various compositions. The raw materials of the materials are bar stock,  ingot, metal powder and liquid metal. The  ratio of the cross-sectional area of the metal before deformation to  the cross-sectional area after deformation is called the forging ratio. Correct  selection of forging ratio, reasonable heating temperature and holding  time, reasonable initial forging temperature and final forging  temperature, reasonable deformation amount and deformation speed have a  great relationship to improve product quality and reduce cost. Generally, small and medium-sized forgings use round or square bars as blanks. The  grain structure and mechanical properties of the bar are uniform and  good, the shape and size are accurate, and the surface quality is good,  which is convenient for mass production. As  long as the heating temperature and deformation conditions are properly  controlled, high-quality forgings can be forged without requiring large  forging deformation.