In the process of cutting titanium, the precautions are

In the process of cutting titanium, the precautions are:
(1) Due to the small elastic modulus of titanium investment casting, the deformation of the workpiece clamped in the processing of large deformation and stress, will reduce the machining accuracy of the workpiece; workpiece clamping force installation should not be too large, increase aid support when necessary.
(2) If using liquid hydrogen cutting, the cutting process will decompose at high temperatures to release hydrogen embrittlement caused by absorption of titanium; it may cause high temperature titanium stress corrosion cracking.
(3) the use of cutting fluid chlorides are also likely to break down or volatile toxic gases, the use of security measures should be taken, otherwise it should not be used; after cutting should be timely and chlorine-free cleaning agent thoroughly cleaned parts, remove residual chlorine thereof.
(4) prohibits the use of lead or zinc-based alloy production workers, fixture and titanium contact, copper, tin, cadmium and its alloys are also prohibited.
(5) All workers, fixtures or other devices must be in contact with the titanium tubing clean; titanium parts cleaned off, to prevent contamination of grease or fingerprints, or after the salt may cause stress corrosion.

With regard to the titanium cutting

With regard to the titanium cutting
HB350 hardness greater than titanium bolts machining particularly difficult, less than HB300 is prone to stick a knife phenomenon, but also difficult to cut. However, only one aspect of the hardness of titanium machining difficult, the key is the combined effect of its machinability of chemical, physical and mechanical properties of titanium itself between. Cutting Titanium has the following characteristics:
(1) deformation coefficient is small: This is a significant feature of titanium machining, deformation coefficient is less than or close to one. Chip away the knife sliding friction surface greatly increases the previous accelerated tool wear.
((3) cutting force per unit area on the big: the main cutting force of about 20% smaller than when cutting steel, due to the length of the chip and the rake face contact is extremely short, the contact area on the cutting forces unit greatly increased, likely to cause chipping Meanwhile, because of the small elastic modulus of the titanium alloy, the processing in the radial force prone to bending deformation, causing vibration, increased tool wear and affects the accuracy of parts.
(4) Chilled serious: Because the chemical activity of titanium plates is large, at high cutting temperature, is easy to absorb oxygen in the air and nitrogen to form a hard and brittle skin; while plastic deformation during the cutting process can also cause surface hardening . Chilled phenomenon will not only reduce the fatigue strength of the parts, but also increased tool wear, is a very important feature when cutting titanium.

Application of titanium in the car

Application of titanium in the car：
Titanium has a light weight, high strength, good corrosion resistance, etc., it is widely used in the automotive industry, the most widely used titanium alloy automotive engine systems. The use of titanium alloys engine parts has many advantages.
Low density titanium alloy, can reduce the inertial mass of the moving parts, while a titanium valve spring can increase the free vibration, reduced body vibrations, increase engine speed and output power.
Reducing the inertial mass of the moving parts, so that the friction is also reduced, improving engine fuel efficiency. Select titanium can reduce the load of stress-related components, reduce the size of the parts, so that the quality of the engine and the vehicle is reduced. Reduce inertia mass parts, so that the vibration and noise reduction, improved engine performance. Titanium applied to other member may improve comfort and the aesthetics of personnel cars and the like. Applications in the automotive industry, titanium alloys in terms of energy consumption plays an invaluable role.
Although titanium alloy parts has such superior performance, but from titanium and its alloys widely used in the automotive industry there is a great distance, causes include expensive, good formability and weldability and poor.
The most widely used titanium bar hinder the automotive industry is still the main reason for the high cost.

Titanium uses editor

Titanium uses editor：
Titanium has a high strength and density and small, good mechanical properties, good toughness and corrosion resistance. In addition, poor process performance. Titanium tubing, machining difficulties in thermal processing, and very easy to absorb carbon hydrogen nitrogen and other impurities. There are poor abrasion resistance, complex production process. Titanium industrial production was started in 1948. Require the development of the aviation industry, the titanium industry with an average annual growth rate of about 8% of the development. World titanium alloy production reached 40,000 tons, nearly 30 kinds of titanium alloys. The most widely used titanium alloy is Ti-6Al-4V, Ti-5Al-2.5Sn and commercially pure titanium.
Titanium is mainly used for the production of aircraft engine compressor components, followed by structure rockets, missiles and high-speed aircraft. The mid-1960s, titanium and its alloys have been in general industrial applications, electrodes for electrolysis industry production, power plant condensers, oil refining and desalination heater and environmental pollution control devices. Titanium wire mesh  have become a corrosion resistant structural materials. In addition, for the production of hydrogen storage materials and shape memory alloys.

Performance Titanium

Performance Titanium：
Titanium plate  at low and ultra-low temperature, retains its mechanical properties. Low temperature performance, low interstitial elements of titanium, as TA7, at -253 ℃ still maintain a certain plasticity. Thus, low-temperature titanium alloy is also an important structural materials.
1. The chemical activity of large
Chemical activity of titanium is large, a strong chemical reaction with atmospheric O, N, H, CO, CO2, water vapor, ammonia and the like. Carbon content greater than 0.2%, it will form a hard TiC in the titanium alloy; at higher temperatures, and also the role of N forms TiN hard surface; at above 600 ℃, the high hardness of hardened layer is formed of titanium absorbs oxygen ; hydrogen content increased, brittle layer will form. Absorbing gas produced brittle surface to a depth of 0.1 ~ 0.15 mm, the degree of hardening of 20% to 30%. Chemical affinity of titanium is also large, easy and sticking friction surface.
2. The thermal conductivity of small elastic
Thermal conductivity of titanium λ = 15.24W / (mK) approximately 1/4 of nickel, iron 1/5, 1/14 aluminum, while the thermal conductivity of various titanium electrodes for chlorinator cell decreased by 50% than the thermal conductivity of titanium. Elastic modulus was about 1/2 of the titanium alloy for steel, so the poor rigidity, deformation, and should not be made thin-walled elongated rod member, the machined surface when cutting a large amount of spring back, the stainless steel is about 2 to 3 times, causing severe tool flank friction, adhesion, adhesive wear.

The structure and application of titanium

The structure and application of titanium：

Titanium is an important structural metal in the 1950s developed, titanium because of its high strength, corrosion resistance, and high heat resistance and are widely used in various fields. Many countries recognize the importance of titanium wire alloy materials, have their research and development, and has been applied.
Titanium is the first practical American successfully developed in 1954, because of its heat resistance, strength, ductility, toughness, formability, weldability, corrosion resistance and biocompatibility are good, and become titanium ace alloy alloy industry, which accounts for the use of an alloy of 75% to 85% of all titanium alloys. Many others can be seen as a modification of titanium alloy Ti-6Al-4V alloy.
1950s and 1960s, mainly in the developing high temperature titanium and titanium alloy airframe aviation engine, the 1970s developed a number of corrosion resistant alloys, since the 1980s, corrosion resistant and high-strength titanium alloy has been further development of. Temperature resistant titanium alloys 400 ℃ from the 1950s up to the 1990s 600 ~ 650 ℃.
Appears based alloy, the titanium tube being propelled by the cold end to the hot end of the engine in the direction of the engine using the engine parts. Titanium alloy development to high-strength, high plastic, high strength and high toughness, high modulus and high damage tolerance direction.
In addition, since the 1970s, there was memory alloys, and get increasingly widely used in engineering.

 

 

Titanium has the following advantages

Titanium has the following advantages:
① high specific strength (tensile strength / density), a tensile strength of up to 100 ~ 140kgf / mm2, and the density of only 60% of steel.
② temperature strength, operating temperature of several hundred degrees higher than aluminum, at moderate temperatures can still maintain the desired strength, long-term work at a temperature of 450 ~ 500 ℃.
③ good corrosion resistance, Titanium heat exchanger surface immediately in the atmosphere to form a layer of uniform dense oxide film, the ability to resist the erosion of a variety of media.
④ low temperature performance, low interstitial elements of titanium, at -253 ℃ still maintain a certain plasticity.
⑤ low elastic modulus, low thermal conductivity, no ferromagnetism.