Titanium alloy forging process characteristics

With the continuous progress of modern society, in order to meet the major needs of the healthy development of my country's national economy and the modernization of national defense, large-tonnage, high-precision and high-efficiency forging and deformation equipment with internationally advanced levels have been manufactured. Energy-saving and environmentally friendly heating equipment has been manufactured in It has also been widely used in forging production. At the same time, advanced forging technologies such as hot die forging, isothermal forging, superplastic forging, multi-directional die forging and powder forging have been widely used in production. Roll forging, cross-cross rolling, radial precision forging, extrusion forging, Special forging technologies such as rolling and upsetting have also been widely used. New technologies such as forging CAD/CAM/CAE have been applied in engineering. Engineering research on intelligent forging technology, forging die life prediction technology and forging performance prediction technology is being carried out comprehensively. . With the development of advanced forging technology, the development trends of titanium alloy forging technology include:
①Precision forging technology for complex ultra-thin forgings;
② Near net deformation technology for large integral forgings;
③Highly reliable and low-cost forging technology;
④New material forging technology;
⑤ Composite manufacturing technology based on forging deformation;
⑥Forging intelligent technology (including numerical simulation, forging knowledge system, production automation line and equipment control), etc.
Titanium alloy forging process characteristics
The purpose of forging deformation of titanium and titanium alloys is, first, to obtain the shape and size of the forging that meets the design requirements, and second, to make the microstructure and performance of the forging meet the design technical specifications. However, the quality of titanium alloy forgings is mainly determined by the forging process, which means that the poor microstructure formed during forging deformation of titanium alloys is difficult to improve with heat treatment processes. Therefore, before formulating the forging process, it is necessary to understand the forging process characteristics of titanium alloys. The forging process characteristics of titanium alloys mainly include the following three aspects.

High deformation resistance is one of the remarkable characteristics of titanium alloy forging deformation. Compared with chromium-nickel-molybdenum alloy structural steel, when forging deformation under the same forging deformation temperature conditions, the deformation resistance of titanium alloy is greater and increases rapidly as the forging deformation temperature decreases. Therefore, due to the high deformation resistance of titanium alloys, even if the forging deformation temperature of titanium alloys is slightly reduced during forging deformation, it will lead to a significant increase in deformation resistance, as shown in Figure 1. Therefore, choosing a reasonable forging deformation temperature is the primary task of titanium alloy forging.

Figure 1 Effect of forging deformation temperature on titanium alloy and chromium-nickel-molybdenum alloy

Poor thermal conductivity is another significant feature of titanium alloys. Poor thermal conductivity causes the surface of the titanium alloy billet to cool faster than the interior after it is heated. Improper operation will cause a relatively large temperature difference between the inside and outside of the billet, aggravating the deformation of the titanium alloy billet during forging. Uneven internal and external deformation, and even cracking, will seriously affect the service life and reliability of titanium alloy forgings. Therefore, fully preheating tools that are in direct contact with titanium alloy billets, such as forging dies and clamps, is a very important task in titanium alloy forging production.

Due to the high viscosity and poor fluidity of titanium alloys, lubrication must be strengthened during forging and deformation of titanium alloys. Otherwise, mold sticking and material backflow will occur. At the same time, the deformation resistance will increase significantly due to the increase in friction, and sometimes stickiness will occur. die and tear the forging. Experimental research results show that without lubricant, the friction coefficient of titanium alloy during high-temperature upsetting is 0.5. When glass lubricant is used, the friction coefficient of titanium alloy during high-temperature upsetting is 0.04~0.06. Therefore, using reasonable lubricants during titanium alloy forging is an important measure to ensure the quality of titanium alloy forgings.
Statement: The article is excerpted from MCC Nonferrous Technology Network