Cold drawing processing technology of titanium rod and titanium wire
Titanium alloy is an ideal structural material due to its excellent mechanical properties such as high strength and high toughness. In order to achieve a good fixed connection effect, the material must have high tensile strength, as well as good plasticity and bending properties. The traditional method uses cold-drawn stainless steel wire, but the material has poor plasticity, with an elongation of less than 5% and poor bending characteristics. Researchers use Ti-6Al-4V titanium alloy, through reasonable regulation of interstitial element oxygen in the alloy, and adopt the method of hot drawing of rolled billet to prepare ultra-high strength TC4 titanium alloy wire, and analyze different oxygen content and process control The impact on the mechanical properties of materials in order to obtain the best preparation method.
Through the research on the cold drawing process of titanium rod and titanium wire, the influence of the pretreatment process and die parameters before cold drawing of titanium rod and titanium wire on the forming of the blank is analyzed. By selecting reasonable cold drawing process parameters, Realize the cold drawing production of titanium alloy at room temperature. The composition detection and structure analysis of the titanium rod blank produced by hot drawing showed that the grain structure of the titanium rod and titanium wire was broken after hot drawing and incomplete recrystallization occurred, and the grains were relatively small and equiaxed. The direction of tissue rheology is not obvious, which provides favorable conditions for the cold drawing deformation of titanium wire. The fracture of the titanium wire after hot drawing showed obvious plastic fracture characteristics. With the increase of deformation, a large number of holes appeared at the bottom of the dimple. The overall performance of the blank is good after annealing treatment at 760℃ for 1h, and a uniform and dense light yellow oxide film is formed on the surface of the blank under the premise of ensuring the annealing quality.
The titanium alloy rod blank undergoes a surface pretreatment process before drawing, and the phosphate lubricating coating and oxalate lubricating coating are successfully prepared, the thickness of which is 2μm and 20μm, respectively. The adhesion of the agent provides a good carrier, and at the same time it can isolate the direct contact between the blank and the mold. Through the numerical analysis of the titanium rod cold drawing process, the shape parameters of the rod and wire cold drawing die within a certain size range are determined. When the working cone angle is 10-12°, the deformation force is in a lower range. Through the cold drawing process experiment of titanium rod, it is found that the effect of the oxalate lubricating coating is better, and the surface quality of the drawn blank obtained is higher. After four consecutive passes, the total deformation of the blank reaches 45%, achieving mass production. Claim. After the titanium rod is cold-drawn, the strength increases and the elongation decreases, and an obvious work hardening effect occurs. After the annealing treatment, the plasticity of the blank is restored without affecting the next cold-drawing process. The crystal grain structure of the titanium alloy rod is equiaxed after cold drawing and annealing, and the degree of equiaxation increases with the increase of deformation.