Microstructure and Mechanical Properties of GR5 Titanium Alloy Titanium Plate
GR5 Ti6Al4V Titanium has moderate room temperature and high temperature strength, good creep resistance and thermal stability, high fatigue properties and resistance to crack propagation resistance (seawater), as well as good fracture toughness and hot salt stress Corrosion performance, suitable for a variety of pressure processing methods forming, and a variety of ways for welding and machining. As a multi-purpose material, Ti6Al4V titanium alloy has been in the aerospace industry and civilian industry has been used extensively. The experiment chooses the large-scale ingot of Ti6Al4V titanium alloy produced by Baoji Xinglong Titanium Industry. The samples were sampled and tested by the chemical composition. The average value of the three samples was (mass fraction. %), and the average value of the three samples was measured. Al6.42, V4.09, Fe0.02, O0.20, Ti margin. It can be seen that the main components of Ti6Al4V titanium alloy large-scale ingot elements Al, V and impurity elements Fe, O uniformity of uniformity, no segregation, to meet the high quality, larger size sheet uniformity requirements of the composition.
The use of multi-fire upsetting free forging process will be forging into the ingot forging, forging equipment for the 45MN fast forging machine, forging finished slab size of 150mm 1060mm 1500mm. The slabs were cut along the cross section at about 100mm from the edge of the slab to observe the slab transverse low magnification and were graded according to the GJB 2505A-2008 standard. According to the requirements in the titanium slab at different locations to take autobiographic samples, tensile specimens. Depending on the standard of GJB1538A-2008, the microstructures were tested and rated. The heat treatment was carried out at 810 / 1.5H / AC. The samples after heat treatment were according to GB / T228-2008 Standard for room temperature tensile test. The test results are as follows:
(1) Titanium Plate at different parts of the room temperature tensile properties are met the requirements of the index, and have a greater wealth, tensile strength than the standard requirements of more than 100MPa, yield strength higher than the standard value of 87MPa or more, elongation and cross section shrinkage The rate also has a certain surplus. The difference between the measured data and the elongation index is low, which indicates that the forging process has achieved good control of slab forming uniformity.
(2) transverse low magnification of titanium slab is blurred crystal, which shows that the forging has good forging. Grain is broken and the degree of grain refinement is high.
(3) The transverse microstructure of the titanium slab is mainly equiaxed α, and the average size of the primary α of the slab is slightly larger than that of other parts. The reason for the existence of organizational differences is that the deformation of the slab core is lower than that of other parts, and the degree of grain fragmentation is relatively low. The longitudinal microstructures of titanium slabs is mainly α, the metal flow lines along the extensional direction are obvious, the grains are fine and uniform, and the consistency of each sampling site is good.
