Do you know the advantages of titanium alloy screws compared with other metal materials? We do not know it does not matter, today Xiao Bian tell you about titanium alloy screws and other metal materials, what are the strengths, like a friend come and see Oh!
1. Titanium alloy screws have higher specific strength (tensile strength/density) (see figure), tensile strength up to 100-140kgf/mm2, and density only 60% of steel.
2. The medium temperature intensity is good, the operating temperature is a few hundred degrees higher than that of the aluminum alloy, and the required strength can still be maintained at a moderate temperature, and the long-term operation can be performed at a temperature of 450-500°C.
3. Corrosion resistance is good, titanium surface in the atmosphere immediately constitute a layer of uniform and fine oxide film, have the ability to resist a variety of media corrosion. In general, titanium has excellent corrosion resistance in oxidizing and neutral media, and has superior corrosion resistance in seawater, wet chlorine, and chloride solutions. However, titanium has poor corrosion resistance in reducing media such as hydrochloric acid.
4. Titanium alloy screws have good low temperature function, and titanium alloys with extremely low void elements, such as TA7, can still maintain certain plasticity at -253°C.
5. Titanium alloy screws have low elastic modulus, low thermal conductivity, and no ferromagnetism.
6. Titanium screws have high hardness.
7. Poor stamping, excellent thermoplasticity.
Titanium alloy screw heat treatment Titanium alloy screw through the adjustment of heat treatment process can obtain different phase composition and arrangements. It is generally thought that the fine equiaxed arrangement has better plasticity, thermal stability and fatigue strength; the needle-like arrangement has higher durable strength, creep strength and fracture toughness; the equiaxed and needle-like mixing arrangement has better induction function.
Commonly used heat treatment methods include annealing, solution and aging treatments. Annealing is to eliminate internal stress, improve plasticity and arrange stability in order to achieve a better induction function. Generally, the annealing temperature of α alloy and (α+β) alloy is selected from 120°C to 200°C below the change point of (α+β)→β phase; the solid solution and aging treatment is rapid cooling from high temperature region to obtain martensite α′ Phase and sub-stable β phase, and then in the warm temperature zone to make these sub-stable phase differentiation, to obtain α phase or compound and other fine dispersed second phase point, to achieve the purpose of strengthening the alloy. The quenching of the general (α+β) alloy is performed at 40 to 100°C below the change point of (α+β)→β phase, and the quenching at subatmosphere β alloy is at 40 to 80°C above the change point of (α+β)→β phase. get on. Aging treatment temperature is generally 450 ~ 550 °C. In addition, in order to satisfy the special request of the workpiece, two layers of annealing, isothermal annealing, β heat treatment, deformation heat treatment and other metal heat treatment processes are also used in the industry.