Titanium CNC machining is a popular process for making precise parts out of titanium. Titanium is a commonly used metal in CNC machining projects. It is employed in various applications, such as jewelry, aircraft, power plants, medical equipment, missiles, and many more.
This article will discuss everything you need to know, including all CNC machining operations, factors to consider during titanium CNC machining, advantages, applications, and surface finishing options.
What is Titanium?
Titanium is a lightweight, strong, durable, and highly corrosion- resistive metal. It offers superior toughness and hardness along with a low coefficient of friction and wears resistance.
The accurate machining of Titanium is quite challenging, especially when it needs to be manipulated into intrinsic shapes. Therefore, CNC machining is the ideal option for titanium manufacturing.
Titanium Alloy Grades
Titanium sheets
In the market, CNC-machinable Titanium comes a range of grades (Grades 1-10). As you go up the number, strength increases simultaneously.
| Grade | Description |
| Grade 1-4 | It is the purest form of Titanium among the grades. It is lighter than steel and offers high strength than that. |
| Grade 5 | It is compatible with high working temperatures, which makes it appropriate for chemical processing, aerospace, marine, and many more applications. |
| Grade 9 | Titanium alloy of grade 9 is famous for its high strength and weldability. It can work in high temperatures without losing its mechanical properties significantly. |
Titanium Alloys for CNC machining
| Ti-6Al-4V | It offers a high strength-to-weight ratio and is suitable for aircraft parts. |
| Ti-6Al-4VEli | It offers excellent bio-compatibility properties, making it ideal for medical applications. |
Titanium CNC Machining
Carbide cutting tools with a circular arc transition tip are used for the Titanium CNC machining. Hardness-level of Titanium requires a more brutal machining tool. These tools contain a slight front angle and a large rear angle to optimize the touching length (The machining area from the cutting tool area). A considerable touching length lowers the friction.
The round tip creates sharp corners without burnout and chipping. CNC machining of Titanium involves low machining speed and feed rate if a significant cutting depth is required.
High cutting speeds are also possible. However, keeping an eye on temperature increment in the workpiece and tool is suggested. Sometimes, the high cutting speed can cause chipping & fracture because of the reaction between chips and tool.
Our titanium CNC machining
CNC Milling of Titanium
Part from CNC-milling
CNC milling creates the required shape from a workpiece by removing material with the rotatory tool. It is crucial to consider various properties of Titanium and act accordingly to mill the titanium workpiece. The high strength and hardness of Titanium require tough milling tools such as those made with cement carbide & hardened steel. The immense force on the titanium workpiece can cause the overheating problem in milling tools, resulting in the formation of burrs and dimensional inconsistency.
To avoid overheating in CNC milling, the lubricant must be applied continuously. In addition, machining speed also can be reduced if that does not limit the final requirements, such as surface finish & tolerances.
Vibration is another outcome of Titanium CNC milling. The high strength causes vibration in cutting tools, which can shorten the life span. Again, Cement carbide tools are the best choice to minimize the vibration.
CNC Turning of Titanium
Titanium CNC turning In CNC turning, the workpiece rotates, and the tool fed away the material to convert it into the required geometry. The high mechanical strength and toughness of Titanium demand a slower turning speed. High RPM of the workpiece can cause the formation of craters and grooves. In addition, excessive heat contributes to chip formation.
- Cutting fluid minimizes the temperature rise, so use the appropriate coolant.
- Fine-grained carbide tools are the go-to option for CNC turning.
- It is recommended to consider 15 to 20% of blade diameter while choosing cutting depth.
CNC Drilling of Titanium
Moderate speed is suitable for titanium drilling because high speed causes vibration and overheating problems. Titanium’s high strength and hardness require Carbide tipped drill bits to create an accurate hole.
Drilling the deep hole in Titanium is challenging. Hardness can affect the straightness of the hole. If you need a deep hole, you can use a hollow-core cutting tool to create a straight-circular hole (Safian Sharif, 2012).
Variables of Titanium CNC machining
CNC Machining of Titanium has some challenges because of some mechanical properties of Titanium, such as poor thermal conductivity, mechanical strength, and hardness. To obtain the best machining result, there are different considerations.
- Excessive heat
When determining the feed rate and cutting speed, it is crucial to consider excessive heat. Titanium is not like copper or aluminum. It produces a large amount of heat, which can damage the tool and the quality of the part.
In addition, the cooling set-up should be the priority, and RPM must be adjusted when the temperature exceeds the expected range.
- Appropriate tool path
The basic principle of the tool path is that the CNC machining tool should always engage the titanium workpiece. The optimization of the tool part ensures less cycle time and quality. For instance, setting the tool path in a cyclic pattern combination can optimize groove creation.
- Holding of workpiece
Titanium workpieces need to be tightly gripped with rigid work-holding arrangements in a way that does not cause machining to stop. An improper grip (either too loose or too tight) can harm a workpiece and a CNC cutting tool.
- Built-up edge
Built-up edge is another issue with Titanium CNC machining. The chips can stick to the tool, so frequent removal is necessary to avoid this issue. High-pressure coolant can be applied to get rid of the chips.
Advantages
CNC machining of Titanium has various advantages, such as excellent dimensional accuracy, complex shapes, cost-effectiveness, quick lead time, high strength-to-weight ratio, and many more. Let’s briefly go over a few of them.
- Biocompatible
Titanium has several medical applications because of its biocompatible corrosion resistance & non-toxic nature. It can be combined with iron, aluminum, molybdenum, nickel, and other elements to make it stronger.
- Superior corrosion resistance
CNC machined titanium is highly corrosion resistive. So, it does not wear for a long time and withstands any level of dampness & maritime conditions.
- High strength-to-weight ratio
Titanium is a lightweight metal with a high strength-to-weight ratio., h 1.3 times aluminum and 3.5 times stainless steel. This advantage makes it ideal for aerospace applications.
You might want to Know:
- Complicated shapes
CNC machining allows to manipulation of Titanium into complex shapes. Using highly rigid Carbide or diamond tools can convert any complex 3D design into reality with a high degree of dimensional accuracy.
- Cost-effective
Creating titanium parts with CNC machining is more cost-effective than conventional manufacturing approaches and cutting-edge technology like 3D printing.
Related:
CNC Machining: Best Approach for Manufacturing
- Precision
CNC machining creates accurate parts for several applications. An advanced 5-axis CNC machine can maintain tolerances as low as ±0.0005″.
Applications
- Aerospace
Titanium parts in an airplane
The corrosion-resistive nature and high strength make Titanium suitable for aerospace applications. Other properties such as fatigue strength, toughness, temperature resistance, and wear resistance aid in the functionality of titanium aerospace parts. CNC machining of Titanium has a significant role in the creation of Engine blades, landing gear, shafts, interior structures, compressor wheels, connecting rods, engine compartments, and many more.
- Medical
Titanium exhibits chemical inertness and biocompatible properties, which allow it to use in medical applications. The high accuracy of medical implants & surgical equipment can be achieved by CNC machining. Some typical medical applications of Titanium include Bone growth stimulators, spinal fusion devices, bone plates, orthodontics, and fake body parts.
- Marine
CNC machining of Titanium also has significant use in the marine industry. Superior corrosion resistance and lightweight character suit well for marine applications, such as decks, shackles, snap hooks, pressure vessels, submarine probes, and many more.
- Automotive
Various automotive parts of Titanium
Sport and luxury cars widely use Titanium because of impact resistance and durability. It is used in frames, fasteners, mufflers, exhaust Pipes, engine valves, load-bearing springs, and many more.
- Others
In addition to all these applications, titanium CNC machining is applicable in oil & gas, construction, architecture, jewelry, sports, EV, and other industries.
Surface Finishing Options
CNC machining of Titanium can leave tool marks and some tiny burrs on the machined surface. However, it offers an excellent as-machine surface finish ( Ra value as low as 1.20 μm ) (G.A. Ibrahim, 2003). If aesthetic appeal matters, there are different surface finishing options.
- Plasma Electrolytic Oxidation
- Plasma Nitriding
- Anodizing
- Polishing
Final Thought
Titanium is a lightweight metal with excellent corrosion resistance, high mechanical strength, hardness, biocompatibility, and other unique mechanical & chemical properties. These properties make it suitable for automotive, aerospace, medical, construction, architecture, marine, and several other applications. Almost all titanium parts can be created with CNC machining for these industries.
Prolean is a dedicated Titanium CNC machining service provider. We have cutting-edge CNC machining technology and expert engineers, so send us your design; you are just a few steps behind in getting your parts.
FAQ’s
Why is Titanium difficult for CNC machining, which Has Higher Machinability, Steel or Titanium?
The properties of Titanium, including its hardness, low thermal conductivity, and high mechanical strength, make it challenging for accurate CNC machining. It requires consideration of various operating variables.
What are the essential considerations for the CNC machining of Titanium?
Sometimes a minor change in operating variables can change the quality of the machined part, and you must consider different factors for quality titanium parts. The variable includes heat generation, formation of built-up edge, cutting speed, feed rate, and many more.
Why choose CNC machining for titanium parts?
CNC machining of Titanium provides excellent dimension accuracy and tolerances as low as ±0.0005″. In addition, it can create complex shapes, is cost-effective, and offers quick lead time.
What are the common titanium alloys for CNC machining?
Ti-6Al-4V and Ti-6Al-4VEli are the most used titanium alloys in CNC machining projects. However, there are ten different grades (grades 1 to 10) of titanium alloys with variations in properties.
Bibliography
- A. Ibrahim, C. C. (2003). The Effect of Dry Machining on Surface Integrity of Titanium Alloy Ti-6Al-4V ELI. ScienceAlert.
- Safian Sharif, E. A. (2016). Machinability of Titanium Alloys in Drilling. IntechOpen.
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