Characteristics of titanium alloy materials such as titanium rods and titanium alloy rods and types of heat treatment processes for rods

Titanium is very stable in the air at room temperature. When heated to 400-550 °C, a firm oxide film is formed on the surface, which plays a protective role to prevent further oxidation. Titanium has a strong ability to absorb oxygen, nitrogen, and hydrogen. These gases are impurities that are very harmful to metal titanium, and even a small content (0.01% to 0.005%) can seriously affect its mechanical properties. Among the titanium compounds, titanium dioxide (TiO2) has practical value. TiO2 is inert to the human body, non-toxic, and has a series of excellent optical properties. TiO2 is opaque, with high gloss and whiteness, high refractive index and scattering power, strong covering power, and good dispersibility. The pigment made is a white powder, commonly known as titanium dioxide, which is widely used. The appearance of the machined titanium round rod is very similar to that of steel, with a density of 4.51 g/cm3, which is less than 60% of that of steel, and is a metal element with low density in refractory metals. The mechanical properties of titanium, commonly known as mechanical properties, are closely related to purity. High-purity titanium has excellent machinability, good elongation, and area shrinkage, but low strength and is not suitable for structural materials. Industrial pure titanium contains an appropriate amount of impurities, has high strength and plasticity, and is suitable for making structural materials.

Titanium alloys are divided into low-strength and high-plasticity, medium-strength, and high-strength, ranging from 200 (low-strength) to 1300 (high-strength) MPa, but in general, titanium alloys can be regarded as high-strength alloys. They are stronger than aluminum alloys, which are considered medium-strength, and can completely replace certain types of steel in strength. Some titanium alloys can still maintain good strength at 600°C compared to aluminum alloys whose strength decreases rapidly at temperatures above 150°C. Dense metal titanium is highly valued by the aviation industry due to its lightweight, higher strength than aluminum alloys, and its ability to maintain higher strength than aluminum at high temperatures. Considering that the density of titanium is 57% of that of steel, its specific strength (strength/weight ratio or strength/density ratio) is high, and its anti-corrosion, anti-oxidation, and anti-fatigue capabilities are all strong, and 3/4 of titanium alloys are used as 1/4 of the structural materials represented by aviation structural alloys are mainly used as corrosion-resistant alloys. Titanium alloy has high strength and low density, good mechanical properties, good toughness, and corrosion resistance. In addition, the process performance of titanium alloy is poor, cutting is difficult, and it is very easy to absorb impurities such as hydrogen, oxygen, nitrogen, and carbon during hot processing. There is also poor wear resistance and a complex production process. The industrial production of titanium started in 1948. The need for the development of the aviation industry makes the titanium industry develop at an average annual growth rate of about 8%. At present, the annual output of titanium alloy processing materials in the world has reached more than 40,000 tons, and there are nearly 30 kinds of titanium alloy grades. The widely used titanium alloys are Ti-6Al-4V(TC4)'Ti-5Al-2.5Sn(TA7) and industrial pure titanium (TA1, TA2, and TA3).

There are three heat treatment processes for astm b348 titanium rod and titanium alloy rods:

1. Solution treatment and aging:

The purpose is to increase its strength, alpha titanium alloys and stable beta titanium alloys cannot be strengthened by heat treatment, and are only annealed in production. α+β titanium alloys and metastable β titanium alloys containing a small amount of α phase can be further strengthened by solution treatment and aging.

2. Stress relief annealing:

The purpose is to eliminate or reduce the residual stress generated during processing. Prevent chemical attacks and reduce deformation in some corrosive environments.

3. Complete annealing:

The purpose is to obtain good toughness, improve processing properties, facilitate reprocessing and improve dimensional and organizational stability.

Characteristics of titanium alloys for construction

Titanium alloys are widely used in various fields because of their high strength, good corrosion resistance, and high heat resistance. Many countries in the world have recognized the importance of titanium alloy materials, have carried out research and development on them one after another, and have been practically applied by titanium alloy manufacturers.

Grade 5 Ti-6Al-4V Titanium Sheet is also a building material. It is mainly used in the exterior wall decoration of buildings, roof surface decoration, waterproofing, etc. It is also used in building column decoration, monuments, signs, house numbers, railings, pipes, corrosion protection, etc. covered, etc. For example, in 1997, the Guggenheim Museum in Bilbao, Spain used titanium metal panels as the exterior decoration of building.

Titanium alloy material is an alloy composed of titanium and other elements. It was developed in the 1950s and was mainly used in the aviation field. It has the characteristics of high strength, good corrosion resistance, and high heat resistance. Use at a temperature of 600°C.

ASTM F136 6Al-4V ELI Titanium Bar has a satisfactory natural luster, sparkle, different colors after surface oxidation, and excellent corrosion resistance. Because of these characteristics, they were later used as building materials in buildings. However, the price is relatively expensive, and it is generally used in public buildings with relatively high requirements.

Performance characteristics of titanium flanges for chemical ships and aviation

Titanium flange is a non-ferrous or titanium alloy connecting pipe structure. The titanium flange has holes, and the two flanges are closely connected. The flanges are sealed with gaskets. Flanged pipe parts refer to pipe fittings with flanges (joints or joints).

Threaded or welded joints are available. The flange joint consists of a pair of flanges, a gasket, and several bolts and nuts. The gasket is placed between the two flanged glands. After tightening the nut, when the specific pressure of the gasket surface reaches a certain value, the sealing surface is filled unevenly and the connection is tight.

According to the structure, it can be divided into titanium flange, butt welding titanium flange, threaded titanium flange, blind titanium alloy flange, etc.

Product Specifications: Various specifications are produced according to flange standards, or non-standard flanges can be produced according to the drawings provided by customers.

Manufacturing method: free forging, die forging, precision forging, welding.

Inspection method: radiographic inspection, dyeing, flaw detection, hydrostatic test, etc. can be carried out according to customer needs.

The cladding rolling process will bring changes to the production of titanium alloy sheets

The production of domestic titanium alloy sheets is still mostly rolled by the single-piece method. Due to the poor low-temperature plasticity of titanium alloys and large cold deformation work hardening, it is extremely difficult to produce thin plates by the single-piece method. In order to make the rolling process go smoothly and reduce the temperature drop of the metal during the forging process, especially to reduce the chill on the surface of the billet, the die for forging titanium alloy needs to be preheated. Otherwise, the metal temperature drop and surface chill will make the metal not fill the mold groove well and may cause many cracks. Die preheating systems for titanium alloy forging are usually detachable, but sometimes a heating device mounted on the press is also used. Detachable die heating systems are usually gas heaters that slowly heat the die to the desired temperature range before the modules are assembled into the forging equipment. The heating device solidified on the press usually adopts induction heating or resistance heating. With the expansion of the market, the new technology of superplastic forming-diffusion joining of titanium alloy sheet has been widely used.

According to statistics, in the production of TC4 titanium plate, the invisible loss caused by alkaline pickling and grinding is as high as about 30%, the comprehensive yield is only about 35%, and the production cycle is long and the performance is unstable. The deformation rate of the cold rolling degree is not more than 25%, and it requires multiple cold rolling, intermediate annealing, and alkali pickling, and process defects such as cracks, edge cracks, slag removal, and cratering are prone to occur during rolling. Production process of titanium alloy plate (below 1.0mm), titanium alloy cross rolling and beta thermal process, self-developed stack rolling and clad rolling process, titanium and titanium alloy warm rolling technology, self-developed atmosphere protection controllable Cooling gravity creep correction technology and other key technologies for a series of flow rectification processes. In the test of the new production process of TC4 sheet, TC4 sheet with thickness of 0.6mm has been produced by cladding and rolling process, and it has been put into mass production.

Which parts of the tank can be made of titanium alloy

There are many reports on the application of titanium and titanium alloys in tanks in the United States, but in China, the former Soviet Union, and Russia, there are few reports on this aspect. In the 1990s, the Abrams M1 main battle tank and the Bradley M2 combat vehicle of the United States used many titanium alloy parts to replace the Rolled Homogeneous Armour (Rolled Homogeneous Armour). , RHA).

It is said that seven major steel components are replaced with titanium alloy forged ring on the M1A2 main battle tank: rotating turret plate, nuclear warfare, biological and chemical weapons countermeasure system shield, gunner main sight cover, engine top cover, turret pivot mount, command Hatch cover, vehicle commander thermal imaging observer cover. The total mass of these components made of steel was 1591kg. After changing to titanium alloy, the total mass dropped to 1116kg, a reduction of nearly 30%.

The command hatch and top attack armor of the M2 chariot were originally forged from aluminum alloys, and were later made of 100mm-127mm Ti-6Al-4V alloy plates. The attack armor was made of 80mm thick titanium alloy plates. Their mass ratio Steel parts are 35% lighter. The Ti-6Al-4V alloy was smelted in a low-cost electron beam cooling bed furnace, and a low-cost Ti-6A-1.7Fe-0.1Si Timetal 62S alloy was also developed

The effect of laser welding on the surface treatment of titanium rods!

The process parameters of laser welding are difficult to grasp, because the thermal efficiency fluctuates greatly during the welding process, and the surface condition of the welded titanium rod has a great influence on the thermal efficiency: the brighter the surface, the larger the emitted laser light, and most of the laser energy is reflected on other objects. , transferred to the surrounding material or medium in the form of "heat". But thermal efficiency changes suddenly. Before the titanium rod is melted, only about 10%-20% of the light energy is absorbed by the titanium rod and heats the titanium rod. When the temperature rises to the melting point of the weld metal and begins to melt, the light absorption rate of the titanium rod increases sharply . Grade 7 Titanium Rod company tells you that at this time, about 60%-80% of the light capacity is absorbed by the metal, and the sudden change of thermal effect can easily cause the weld to burn through.

In order to avoid or reduce this adverse effect, the grade 5 titanium rod company tells you that you can take corresponding measures, such as welding titanium rods; roughening the surface, using a pulsed laser beam; adjusting the input energy; adjusting the spot size; Pulse width and steepness.

A ruby ​​natural crystal containing aluminum oxide and dissolved with a low concentration of chromium atoms is used as the working material of the laser generator, which is called a solid-state laser generator. If CO2 is used as the working substance of the laser generator, it is called a force gas laser generator.

At present, the power of the laser welding machine is only kilowatts, and it is expensive, the welding cost is high, and the application range is not wide. It is only used for the solder joints of some tiny parts in the manufacture of some instruments and meters, especially when some solder joints are hidden and cannot be welded by ordinary welding methods. Multi-station welding is possible using laser beams, optical fibers and deflection prisms.

Introduction to the characteristics of titanium

Titanium is not toxic, even in large doses, and does not have any natural effects on the human body.

Powdered titanium and planed titanium flakes can easily cause fires and explode when heated in the air. Water and carbon dioxide-based fire extinguishing methods are ineffective against burning titanium; Class D dry powder fire extinguishing agents must be used instead.

When producing or handling chlorine, care must be taken that grade 5 titanium round bar should only be used where there is no dry chlorine around, otherwise it will cause a titanium/chlorine fire. Even wet chlorine is a fire hazard because it can dry out unexpectedly under unusual weather conditions.

A fresh, unoxidized surface of titanium may catch fire when it comes in contact with liquid oxygen. This surface can be formed by the collision of an oxidized titanium surface with a hard object, or within a crack caused by a mechanical strain. Therefore, the use of titanium in liquid oxygen systems is likely to be limited, such as in the aerospace industry.