Room temperature formability of high-strength titanium alloy sheets
High-strength titanium alloy plates usually have high strength and hardness, so their room temperature formability is relatively poor. During the forming process, high-strength titanium alloy plates are prone to problems such as bending, cracking and poor surface quality.
Let's take Ti-6Al-4V alloyT i-6Al-4V alloy plate as an example. The formability of Ti-6Al-4V alloy plate at room temperature is very limited, and the rebound after forming is very large, which makes traditional stamping and pressure Forming brings many problems. Although at high temperatures, the forming limit of Ti-6Al-4V alloy sheets will increase and the springback will decrease, room temperature forming still has great advantages in cost saving. Roll forming is a forming method that uses rotating rollers to gradually deform a metal blank to make a workpiece. It is suitable for structural parts with high forming strength and limited formability. It is increasingly used in the automotive industry. It is mainly used in Suitable for forming ultra-high-strength steel, high-strength steel, etc. Since the springback angle of the material is small during the roll forming process and the springback compensation can be carried out through a simple and easy method, roll forming is an effective method for room temperature forming of Ti-6Al-4V alloy sheets.
Roll forming can form smaller radii and have less springback than simple bend forming. This is mainly because roll forming is a multi-step cumulative deformation process. Gradual multiple deformations can inhibit the growth of cracks and at the same time make the material deform more fully than ordinary one-time deformation. In addition, shape defects that often occur during the rolling process of high-strength steel are relatively rare during the rolling forming process of Ti-6Al-4V alloy. It can be seen that roll forming is a promising process for forming high-strength titanium alloy plates for aerospace and automotive structural parts at room temperature.
In order to improve the room temperature formability of high-strength titanium alloy plates, the following measures can be taken:
1. Preheating: Proper preheating of high-strength titanium alloy plates before forming can improve their plasticity and toughness and reduce stress concentration and uneven deformation during the forming process.
2. Adjust the forming process parameters: Reasonable selection of the forming process parameters, such as forming temperature, pressure, speed, etc., can make the high-strength titanium alloy plate easier to form at room temperature and reduce the possibility of cracking and stress concentration.
3. Use an appropriate forming mold: Design an appropriate forming mold structure and shape so that the high-strength titanium alloy plate can be deformed evenly during the forming process and reduce stress concentration.
4. Surface treatment: Proper treatment on the surface of high-strength titanium alloy plates, such as coating with lubricants or using special surface coatings, can reduce friction with the mold and improve room temperature formability.
5. Heat treatment: Heat treatment can improve the room temperature formability of high-strength titanium alloy plates, making them have better plasticity and toughness.
In summary, although the room temperature formability of high-strength titanium alloy plates is worse than that of ordinary materials, its formability can be improved through appropriate measures to achieve effective forming of high-strength titanium alloy plates.
