The development status of titanium in the bicycle industry in recent years

Bicycle components refer to the crankshaft positioner, pedals, handlebars, etc. connected to the frame. The titanium component industry is developing faster than the Ti-3AL-2.5V frame industry, and most of the components are produced with Ti-6Al-4V, Most of the parts are machined from bars or plates. The purchasing power of Ti-6A1-4V for parts is only 1/3 of that of Ti-3 gusset 2.5V frame, about 10t in 1997. Casting parts can become more and more common, but the development in this area may be slower than the development of machined parts. Titanium suppliers start to provide titanium parts manufacturers with cheap materials. Most of these low-cost bicycle-grade materials are actually Obsolete aviation materials.

The material requirements of the bicycle frame are very simple, but the driving characteristics are particularly critical, which complicates the selection of materials in some aspects. Most transportation vehicles, structural elements and internal facilities and operating elements are separated. Until recently, all bicycles The frame requires structural integrity and suspension function. There is no titanium alloy specially designed for bicycles. Only some materials have been improved for bicycles. Most people consider cost reduction issues and accept titanium components. The main problem is rigidity rather than cost. Ti-3Al-2.5V is the most commonly used titanium alloy for bicycles. Although it is developed for aircraft hydraulic systems, it is due to formability and corrosion resistance. The high fatigue strength to weight ratio and good elongation makes it meet the bicycle market performance standards. Compared with other titanium alloys, the biggest advantage of Ti-3Al-2.5V is the yield strength and easy tube forming. The disadvantage is its price and mold. The ratio of volume to density is poor. It is not easy to extrude Ti-3Al-2.5V as the dominant frame material. Ti-6AI-4V also has a certain attraction, and its modulus and strength are better than Ti- 3Al-2.5V is higher, but it is difficult to process into a tube with a small diameter like a bicycle frame. Ti-15V-3Al-6Cr-4Mo-4Zr is also easy to shape, but its higher density and lower modulus offset its strength The improved advantages.
Grade 7 Titanium Bar     titanium alloy tube     thin titanium plate     titanium block

Development characteristics of titanium alloy materials and titanium product processing technology

Due to the high manufacturing cost of titanium alloys, in order to reduce costs, the competitiveness of titanium alloys in the entire metal material market has been improved at a lower price. It is generally believed that titanium has incomparable superior performance compared to other materials, but the price of titanium often discourages consumers (especially car manufacturers). The emergence of high-quality, low-cost titanium alloys will certainly help the popularization and application of titanium and titanium alloys.

Judging from the application status at home and abroad and the development of titanium processing technology, the plastic processing technology of titanium and titanium alloys will develop in the following directions in the future:

1) High performance, that is, the development of alloys with higher service temperature, higher specific strength, higher specific modulus, better corrosion resistance and wear resistance.

2) Multi-function, namely the development of titanium alloys with various special functions and uses, such as high damping, low expansion, constant resistance, high resistance, resistance to electrolytic passivation and hydrogen storage, shape memory, superconductivity, low modulus biomedical And other titanium alloys, and further expand the application of titanium and titanium alloys.

3) Deepen the research of traditional alloys, improve the practical performance of existing alloys, and expand the application range of traditional alloys through the improvement of equipment and processes.

4) Adopt advanced processing technology and large-scale continuous processing equipment to develop continuous processing technology, direct rolling technology, cold forming technology and near-net forming technology to improve the production efficiency, yield and product performance of titanium alloys.

5) Reduce costs, develop alloys that contain no or almost no precious metal elements, and add cheap elements such as iron, oxygen and nitrogen, and develop titanium alloys that are easy to process and shape, easy to cut, and have cheap alloy elements and master alloys. Develop titanium alloys and use banned materials to increase the recovery rate and utilization rate of banned titanium. This is particularly important for reducing the cost of civilian titanium alloys.

6) Use advanced computer technology to simulate the deformation and processing of the workpiece, predict the evolution of the metal microstructure, and even predict the mechanical properties of the product (yield strength, tensile strength, elongation, hardness, etc.). ), and design or improve molds and tooling; analyze and process test results, reduce test volume, improve work efficiency, and reduce development costs.
machined titanium round rod     titanium foil grade 5     Ti 15333 Titanium Strip     titanium hexagon rod

Application of titanium plate in medicine

There have been successful cases in the application of titanium plates in the medical field. Titanium is a metal that is compatible with the human body. Titanium will be more and more widely used in the medical field in the future.

Among surgical implant materials, titanium and titanium alloy materials have become artificial joints, bone trauma products (titanium intramedullary nails, titanium plates, titanium screws, etc.), spinal orthopedic internal fixation systems, dental implants, Dental trays, orthodontic wires, artificial heart valves, interventional cardiovascular stents and other medical implant products are the materials of choice.

Compared with traditional treatment methods such as small titanium plate, titanium wire internal fixation, single jaw ligation, intermaxillary traction, a titanium plate in the treatment of maxillofacial fractures, it has the advantages of simple operation, small damage, precise and reliable In addition to the condyle and zygomatic arch fractures, an extraoral incision is required. For other mandibular fractures, intraoral incisions are often used. There is no scar on the face and can avoid damage to the facial nerve.

The problem of intermaxillary traction during titanium plate internal fixation. We believe that intraoperative intermaxillary traction can provide the correct reduction of the fracture end and a good occlusal relationship, and it can also prevent drilling. When the titanium screw is installed, the fracture segment will be displaced again. The occlusal relationship is disordered. Except for the cases of combined mandibular fractures, which need to be assisted for about 1 week after internal fixation, traction and fixation are generally not required after other fracture fixation. Because of the short traction time, it is very difficult for patients. The temporomandibular joint has little effect on the function, easy to maintain oral hygiene, can eat, is conducive to nutrition and wound healing of patients, and at the same time greatly reduces the pain of patients compared with the past.
Ti 6Al-2Sn-4Zr-6Mo Titanium Rod     titanium flat bar     titanium alloy rod     titanium flat rod

What are the chemical element classifications of titanium tubes

Titanium tube is an allotrope with a melting point of 1720°C. When it is lower than 882°C, it has a close-packed hexagonal lattice structure, called α titanium; above 882°C, it has a body-centred cubic lattice structure, called β titanium. Using the different characteristics of the above two structures of the titanium tube, adding appropriate alloying elements to gradually change the phase transformation temperature and phase content to obtain titanium alloys with different structures. At room temperature, titanium alloys have three matrix structures, and titanium alloys are divided into the following three categories: α alloys, (α+β) alloys and β alloys.

Titanium tube is a single-phase alloy composed of α-phase solid solution. It is α-phase no matter at normal temperature or at higher practical application temperature, with stable structure, higher wear resistance than pure titanium, and strong oxidation resistance. At a temperature of 500°C to 600°C, it still maintains its strength and creep resistance, but cannot be strengthened by heat treatment, and its room temperature strength is not high. It is a single-phase alloy composed of β-phase solid solution. It has a high strength without heat treatment. After quenching and aging, the alloy is further strengthened. The room temperature strength can reach 1372 ~ 1666 MPa, but the thermal stability is poor and it is not suitable for use at high temperatures.
grade 5 titanium sheet     titanium rivet     titanium exhaust tube     Grade 23 Titanium Tube

The influence of alloy elements in titanium plate and tube on welding performance

The welding seam and heat-affected zone have a high temperature after welding, and the cooling rate is very fast under the influence of the surrounding base material. Therefore, after fusion welding of titanium plate and titanium tube, it is easy to produce metastable structures such as martensite a', a", quenched ω phase and metastable β. In alloys with a small content of β stable elements, thick needles Martensitic structure will reduce plasticity. Quenching omega phases in alloys with more β-stabilizing elements will cause weld embrittlement. These meta-stable structures also have an adverse effect on welding performance. Use reasonable welding specifications and welding The post-heat treatment system can reduce or even eliminate this effect.

The composition of the alloy has a great influence on the welding performance. When welding with a welding wire with a high content of β-stabilizing elements, compared with the base metal, the plasticity reduction of the weld is generally more severe than that of the less β-stabilizing element. As their strengthening ability increases, the more serious the reduction in plasticity, the lower the welding performance. Generally speaking, the weldability of a-type titanium plate is better, but the tendency to generate pores and cold cracks is greater; the weldability of a+β-type titanium plate is slightly worse, and it becomes better with the decrease of β-stabilizing element content; The thermally stable β-type titanium tube has better overall performance without heat treatment after welding. Heat-treatable beta alloys tend to have a sharp decline in plasticity after aging of the weld, and it is difficult to obtain good comprehensive properties.

In summary, in order to obtain high-quality welded joints in titanium plates and tubes, the following points must be paid attention to:

(1) Strictly control the harmful impurities in the base metal and welding materials (including filler materials and oxygen-free flux), especially the content of interstitial elements such as hydrogen, oxygen, nitrogen, and carbon. Strictly clean the workpiece, welding materials and equipment before welding;

(2) Use high-purity inert gas, oxygen-free flux or vacuum conditions to protect the weld and heat-affected zone so that it will not be contaminated by gas during welding and cooling;

(3) Use welding specifications with low heat input as much as possible to reduce the tendency of a metal to overheat; for different alloys, choose a suitable post-weld heat treatment system to adjust the structure and mechanical properties of the weld and heat-affected zone.
Grade 7 Titanium Sheet     Titanium Wing Nut     titanium seamless tube     Grade 7 Titanium Tube

Main features of titanium rod and titanium alloy material processing

Titanium rods and titanium alloys have high chemical activity. Titanium rods and titanium alloys easily react violently with oxygen, nitrogen and other oxygen-containing gases at high temperatures. When heated in air, the surface of the blank forms an oxide scale and a surface getter layer. Titanium rods and titanium alloys are easy to absorb hydrogen when heated, which causes difficulties in the processing of certain types of titanium alloy materials.

Titanium rods and titanium alloys have poor thermal conductivity. The thermal conductivity of titanium rods and titanium alloys is usually only 1/15 of that of alloys and 1/5 of that of steel. The lower thermal conductivity results in a large temperature difference between the ingot and billet section in the hot B inch, which produces a large thermal response, and cracks will form in severe cases. Therefore, the heating speed must be limited, and the temperature change, deformation speed, Deformation rate, deformation equipment.

Polycrystalline transformation of titanium rods and titanium alloys. Titanium has a-β phase transition. Heating top temperature can significantly increase plasticity and reduce deformation resistance, but the deformation of the β zone is not good enough to obtain a structure with good performance.

The cold deformability of titanium alloy is low. Cold working deformation of most titanium alloys is difficult. A little preheating (to 200~300T) can significantly reduce the deformation resistance and improve plasticity.

Titanium is easy to bond and deform tools. This tendency tends to deteriorate the surface quality of the processed material and puts forward more stringent requirements on the deformed tools and molds and process lubrication.

High yield ratio and low elastic modulus. Straightening in a cold state is very difficult.
Ti 6246 Titanium Rod     titanium alloy bar     bending titanium pipe     Titanium Rotary Target

The titanium tube is heat-treated to remove residues

When the hydrogen content in the titanium tube is too much, the impact toughness and notched tensile strength will drop sharply due to brittleness. Therefore, it is generally stipulated that the hydrogen content in the titanium tube should not exceed 0.015%. In order to reduce the amount of hydrogen absorption, fingerprints, rolling mill marks, grease and other residues should be removed before heat treatment. There is no moisture in the atmosphere of the heat treatment furnace. If the hydrogen content of the titanium tube exceeds the allowable value, it must be removed by vacuum annealing. Vacuum annealing for dehydrogenation is generally held at 538-760°C and pressure lower than 0.066Pa for 2-4 hours.

When the temperature does not exceed 540°C, the oxide film on the surface of the titanium tube will not be significantly thickened. At higher heat treatment temperatures (above 760°C), the oxidation rate will increase rapidly, and oxygen can expand into the material to form a diffusion layer— Pollution layer. The high brittleness ratio of the oxygen contamination layer causes cracks and damage on the surface of the part. There are mechanical processing methods (such as sandblasting, house cutting, etc.) or chemical methods such as pickling and chemical milling to remove the oxygen pollution layer. During the heat treatment, the heating time should be as short as possible while ensuring the heat treatment of the meteorite. It is carried out in a vacuum furnace or an inert gas (argon, nitrogen, etc.) heating furnace. The appropriate application can also avoid or reduce the pollution caused by the titanium tube parts being heated in the air furnace.

Gr36 Ti45Nb Titanium Bar     Gr23 Ti-6Al-4V ELI Titanium Wire     ERTi-12 Titanium Welding Wire     Gr23 Ti-6Al-4V ELI Titanium Pipe