Shaanxi Yunzhong Industry Development Co.,Ltd
Address: NO.128 Gaoxin Road, Baoji City, Shaanxi Province of China
Because of its high strength, light weight, good structural rigidity and other advantages, titanium plate has been widely recognized. High strength titanium alloy Ti-6Al-4V not only can be used in aviation field, but also is an important candidate material for structural parts in other industrial fields such as automobile, chemical industry and so on.
The formability of Ti-6Al-4V alloy sheet at room temperature is very limited, and the springback is very large, which brings a lot of problems to the traditional stamping and pressure forming. In spite of the high temperature, the forming limit of Ti-6Al-4V alloy sheet will be improved, the rebound will be reduced, but the room temperature forming has a great advantage in saving cost.
Rolling is a use of rotating rolls and metal blank gradually deformed workpiece is made by forming method, suitable for forming high strength and limited structure forming, are more and more applications in the automotive industry, mainly used for forming ultra high strength steel, high strength steel and so on. In the process of rolling forming, the springback angle is small and can be compensated by a simple and easy method.
Therefore, the rolling process is an effective method for Ti-6Al-4V alloy sheet at room temperature. To this end, Ossama and other 820 mm after annealing treatment of 2 Ti-6Al-4V thick high strength alloy sheet at room temperature forming and springback behavior of laboratory research.
The original microstructure of the Ti-6Al-4V alloy plate is composed of 93.86% equal axis alpha phase and 6.14% beta phase, the average grain size is 1.3 mu m + 0.7 mu m. Room temperature tensile test results show that the anisotropy is larger, with the rolling direction of 45 degrees, the yield strength of the sample is the lowest, the elongation rate is higher, and when the ultimate strength is reached, the specimen will soon break.
The forming limit test in a hemispherical punch device, hemisphere punch diameter of 60 mm. Using the optical strain measurement system "Vario Autogrid" with 4 advanced CCD cameras to record the complete deformation history of each specimen. The deformation behavior of different strain paths was tested by designing different sample shapes. Experiments found that all specimens are in the top of the hemispherical punch suddenly fracture, fracture with no apparent necking phenomenon, indicating that the formability of the alloy at room temperature is very limited.
The deformation behavior of Ti-6Al-4V alloy at room temperature bending and rolling at room temperature were compared and analyzed. The results show that the bending test and the bending radius of the V bending test are 9 mm and the minimum bending radius is 7.51 mm, which is increased by more than 15%. The rolling process can be formed with a smaller radius and smaller than the simple bending process. This is mainly due to the rolling forming is a multi-step process of cumulative deformation, and progressive deformation can inhibit the growth of cracks, while the deformation of the material is more adequate than the ordinary one.
In addition, in the process of high strength steel rolling, the shape defects are relatively few in the Ti-6Al-4V alloy rolling process. Visible, rolling forming is a high strength titanium alloy sheet for aircraft and automotive structural parts at room temperature.