What are pure titanium and titanium alloys?
Titanium is a kind of bridge that combines the properties of steel and aluminum. Lightweight (almost 2 times lighter than steel), strength (2 times stronger than aluminum), and high resistance to corrosion (almost like platinum) – these properties forced scientists to pay attention to this material and find industrial applications for it.
In the early 1950s, titanium alloys were developed, which, due to their unique strength-to-weight ratio, were widely used in the aerospace and defense industries.
Due to the high melting point (1660 ± 20 °C), as well as high viscosity (titanium tends to stick to the cutting tool during machining), initially, the production of cnc machining titanium parts were a rather complicated and very expensive process, so its use was limited.
However, in recent years, new technologies have greatly simplified this process, and increasing production volumes have reduced the cost of titanium so that the unique combination of strength, lightness, and corrosion resistance of this material has become available to many other industries.
TITANIUM ALLOYS
Titanium without impurities is called technically pure titanium (Titan grade 1 – 4 according to the international classification). Pure titanium has been widely used due to its high corrosion resistance.
Invisible to the naked eye, a thin (about 10 nm) oxide film instantly covers the material in the presence of oxygen or moisture, so that titanium is quickly restored in case of damage. This property of titanium makes it resistant to corrosion, including in the most aggressive environments.
Titan grade 5 is the most common titanium alloy. Although its corrosion properties are slightly inferior to commercially pure titanium, this alloy can resist corrosion in seawater, chlorine solutions, oxidizing acids, and sodium hypochlorite.
Added to the composition of the alloy: Aluminum 6%, Vanadium 4%, Iron 0.25% (max), and Oxygen 0.2% (max) – it is thanks to these additives that the alloy becomes even stronger while maintaining the rigidity and thermodynamic properties of pure titanium. Titan Grade 5 is the basis for 70% of titanium alloys being smelted.
cnc machining titanium is characterized by being very strong, having a silvery color, and also being extremely resistant to the rusting process. Because a TiO2 film forms on the metal surface of cnc machining titanium parts, it has good resistance to all external influences. Only the influence of substances that contain alkali in their composition can negatively affect the properties of titanium. Upon contact with these chemicals, the raw material loses its strength characteristics.
Due to the high strength of the product, when turning titanium, it is necessary to use a tool made of an ultra-high-strength alloy, as well as create other special conditions when working on a CNC lathe.
Advantages of Machined Titanium Parts
Titanium is called the metal of the 20th century, the metal of the future, or the metal of supersonic speeds. Yielding to some other metals in lightness, strength, and resistance to corrosion, titanium alloys remain unique in terms of their properties.
These are the only materials that combine all of the listed properties and thus, as it were, work for three. It is this combination that justifies all the disadvantages of Ti-alloys, more than offsetting the costs and difficulties associated with their production, processing, and application.
Multiple Applications of Titanium Parts
Since its inception, the production of cnc machining titanium parts has had an exclusively military focus. In the United States, this metal was figuratively called the “child of war.” In terms of production growth rates, titanium has not equal to other industrial metals.
Titanium is somewhat heavier than aluminum, but it is also much stronger than it, and for the same parts of an aircraft, titanium is required less than aluminum, so the design becomes lighter. Thanks to the use of titanium instead of aluminum, the mass of the aircraft can be reduced by 20-25%.
Parts made of titanium alloys used in gas turbines can withstand heat up to a temperature of 480°C and make it possible to reduce the weight of the turbine of a subsonic engine by 200 and of a supersonic engine by 100 kilograms.
In the engines of modern jet aircraft, the amount of titanium used is from 15 to 35 percent of the total mass. These amounts of titanium provide a significant reduction in the mass of the engine, which, in turn, reduces the total mass of the aircraft structure by 5-10 times!
After aviation, the main share of the use of titanium alloys falls on the needs of rocket technology and marine shipbuilding. Due to its exceptionally high corrosion resistance, commercial titanium is in some cases indispensable in the chemical and medical industries.
Titanium Alloys in Aviation Industry
Research and development of cnc machining titanium parts for the needs of aviation technology, including aircraft gas turbine engines (GTE), have been carried out for more than 60 years. Initially, the mass of titanium parts was 5–10% of the total mass of GTE; in modern designs, the weight fraction of titanium alloys is about 40%.
In aircraft engine building, titanium alloys are used mainly for the manufacture of a compressor unit, i.e. for disks, blades, guide vanes, intermediate rings, shafts, etc. In this case, the use of titanium alloys instead of steel makes it possible to reduce the weight of the compressor by 30–35% due to the higher specific heat resistance of titanium alloys.
Common Titanium Grades
Titanium’s high specific strength, excellent mechanical properties, and corrosion resistance make titanium the optimal choice for many critical applications.
Due to the allotropic behavior of titanium, different thermomechanical processing processes produce different microstructural changes, so a small number of titanium alloy grades can provide a wide range of material properties and applications. This situation is particularly remarkable in a+ β-type titanium alloy.
The most widely used titanium alloy grade is Ti-6Al-4V in α+β alloy. This titanium alloy is the most well-known titanium alloy grade for its good combination of properties, although it has relatively poor room temperature ductility and formability compared to steel and aluminum.
The titanium alloy grade Ti-6Al-4V is most commonly used in the annealed condition and has limited cross-sectional dimension hardenability.
Commercially pure titanium grades 1, 2, 3, and 4 are commonly used as bars and billets. The following titanium grades are also commonly available in bar and billet form:
- Ti-6Al-4V
- Ti-5Al-2.5Sn
- Ti-0.2Pd
- Ti -3Al-8V-6Cr-4Zr-4Mo
- Ti-6Al-2Sn-4Zr-2Mo
- Ti-8Al-1Mo-1V,
What Are the Advantages of CNC Machining Titanium Parts?
The machining of high-strength titanium alloys is a major challenge for many workshops. In response to their needs, machine tool designers develop special milling and boring centers with improved stiffness and vibration damping of the spindle, drive, and large machine elements.
This is to minimize undesirable vibrations that degrade the quality of the machined parts and limit the life of the tools.
At present, there are more and more technical manufacturers specializing in five-axis linkage processing. Due to the continuous upgrading of equipment, it can be said that the precision level of processing will be greatly improved, and there are many kinds of material parts suitable for processing
So, what are the main technical advantages of the five-axis simultaneous machining of titanium alloy parts?
The surface is smooth and the processing technology is fine and reliable.
First of all, in the five-axis cnc machining titanium parts, we will pay attention to the smooth workmanship of the surface, so that the processing will be more refined and guaranteed.
Then, there will be a substantial increase in quality and performance, and the finished parts can be strictly up to standard. Therefore, it can be trusted and recognized by customers at the time of delivery, which improves the quality advantage in the market.
According to the requirements of drawings, higher machining accuracy can be achieved.
Of course, in the process of five-axis linkage processing of titanium alloy parts, according to the drawing requirements provided by the customer, the manufacturer has reached the ideal precision standard in the process of processing.
Only every detail size indicated on the drawing can be fully considered during processing. In this way, the processing effect in the factory will be better. In short, the machining accuracy is high, the quality advantage of the factory will become more and more obvious, and the function of each part can be displayed.
Sophisticated equipment, the pursuit of excellence
The equipment technology for the five-axis linkage processing of cnc machining titanium parts is constantly being upgraded, and the introduced equipment has reached an excellent standard. Then, in the process of processing, we will pursue excellence, to make the titanium alloy parts meet the standards in all aspects of the process quality, and the quality will be better.
Benefits of Using Titanium for CNC Machined Precision Parts
The ultimate secret to the success of cnc machining titanium parts is the keen eyes and experienced hands of professionals who oversee the titanium machining process. They draw on decades of experience to ensure that cutting speeds, feed rates, cutting fluids, and tool conditions are perfectly maintained for the precision machining of titanium alloys.
Titanium is comparable in strength to steel but much less dense. This makes it an ideal material for jobs that require high strength but are limited by the weight of the part. The titanium also has different corrosion resistance than steel, which is why it has many applications on ships and submarines. The titanium also has high resistance to high and low temperatures.
This material and its lightweight properties make it an ideal metal for the aerospace industry and for everything from recreational aircraft to ballistic missiles.
Titanium machined parts VS aluminum machined Parts VS steel machined parts
Titanium alloy, which has “strength”, “lightness”, “corrosion resistance” and “heat resistance”, was previously relatively expensive, so it was used in limited fields such as the aircraft and spacecraft industries and nuclear power generation. However, in recent years, the demand for titanium has been increasing year by year due to progress in the reduction of manufacturing costs.
Titanium materials are broadly classified into two types: general-purpose materials and special materials.
As mentioned earlier, titanium has four characteristics:
- corrosion resistance
- heat resistance
- Strength
- lightness
Due to these excellent properties of titanium, titanium is a material used in various fields, mainly in the aerospace, but also in chemical, electric power and desalination, ocean and energy, nuclear fuel, construction and civil engineering, transportation equipment, and consumer products.
Aluminum is the optimal material for the production of parts
The metal is light, ductile, and easy to process. Although it is inferior in hardness to steel, it is less prone to corrosion. If the hardness index of an aluminum alloy suits you, it is better to choose it. So you can not only save on materials but also reduce production time.
On average, it takes three times less time to produce an aluminum part than to produce the same product from steel. The tool wears out less, so production costs are reduced.
If some part can be made of aluminum, then it makes no sense to even consider other materials.
ALLOY (STAINLESS) STEEL PARTS
Alloy steel is divided into:
- containing a small amount of alloying elements – up to 2.49% (low-alloyed);
- containing an average amount of alloying elements – 2.5 – 10% (medium alloyed);
- And contains a large amount of alloying elements – more than 10.1% (highly alloyed).
It depends on the presence of chemical additives such as silicon, copper, tungsten, and others in their composition. Alloy steel parts are used for the manufacture of medical instruments, parts of machines and machine tools, etc. They have an increased resistance to corrosion, which allows them to be used in aggressive environments.
CARBON STEEL PARTS
Carbon steel is classified into:
- low carbon – up to 0.249% carbon;
- medium carbon – 0.25-0.59% carbon;
- High carbon – more than 0.6% carbon.
This directly depends on the carbon content in their composition. Compared with other grades, the content of impurities in carbon steel is minimal. High-strength tools, parts, and mechanisms subjected to long-term high loads are made from carbon steel. Carbon steel parts are firmly connected by welding.
Titanium Machined Parts Surface Finish
cnc machining titanium is a technological process in which the workpiece is given the desired shape, size, and surface finish. This metal is very durable, has excellent corrosion resistance, and has a small mass. These characteristics are important advantages and determine the wide scope of application of titanium alloys and the metal itself in its pure form. It is most often used as a structural material in:
- rocket science;
- manufacturing of aviation equipment;
- Maritime shipbuilding.
At the same time, it is quite difficult to interact with titanium; it requires not only expensive high-power equipment but also a professional approach. Therefore, it is better to entrust the performance of complex work to experienced specialists.
In our work, we use advanced technologies for cnc machining titanium parts, the latest laser, grinding machines, cutters, and other powerful, precise equipment, which guarantees the quality of the final result.
There are several types of titanium machining:
- cutting;
- milling;
- grinding;
- Drilling
Each of these machining has its characteristics and difficulties that must be taken into account when performing the tasks. This is not only the choice of the right equipment, but also its correct configuration, the speed of each task, and other parameters.
Cutting titanium: varieties and features of the process
Metal cutting is the most popular type of material machining, as it allows you to get a workpiece of the desired size, and sometimes shape. There are several types of cutting of this metal, the most popular of which are:
- hydro abrasive;
- sheet metal laser cutting ;
- Mechanical impact.
The latter method is used extremely rarely, mainly if the workpieces have a slight thickness. At the same time, the process requires a large number of post-processing operations and has many contraindications. Therefore, in most cases, cutting of titanium blanks is carried out using laser equipment or abrasives.
The essence of waterjet cutting is that under the influence of a very powerful jet of water, into which solid abrasive particles have been placed in advance, the metal is cut.
The technique has many advantages:
- The ability to receive blanks of any complexity;
- High speed of metal processing;
- The cut is clean, and high-quality while heating the material is not required;
- Minimum waste;
- Work with titanium blanks of large thickness is possible.
Conclusion
cnc machining titanium parts’ high strength, low density, and corrosion resistance are leading to increased use of titanium in various industries such as aerospace, chemical, petrochemical, offshore oil and gas, power generation, desalination, and generally over the past 40 years, combined with engineering, and biomedicine.
It is no longer considered a new metal or unusual only for aerospace applications but is only available to design engineers as high-performance material. Titanium is new metal. Because of its excellent properties, it is widely used in industrial production such as aviation, aerospace, chemical industry, petroleum, metallurgy, light industry, electric power, seawater desalination, ships, and daily life appliances for modern metal.