Lightweight, resistant and biocompatible:
titanium is popular
Occurring relatively frequently in nature but seldom in pure form, titanium is obtained by using a complicated production process. This makes titanium a costly and exclusive product.
It is its properties that nonetheless make this element a coveted commodity in today's industry. Very malleable in pure form with a high durability in a low density (60% in comparison to steel), titanium is simultaneously corrosion and temperature-resistant. Its compatibility when in contact with the human body is also excellent.
Two main categories are differentiated: Titanium alloys where the titanium is alloyed with other metals and pure titanium which contains only minor impurities.
The characteristics
Titanium alloys (degree 5 and higher)
- Example of material: TiAl6V4 (3.7165)
- Corrosion protection: high
- Acid resistance: good
- Good mechanical properties (tensile strength)
- Toughness: high even at low temperatures
- Specific density: low
- Thermal conductivity: low
- Not magnetic
- Biocompatibility: very good
- Machinability: medium to difficult
- Main application areas: watches and jewelry, medical technology, aerospace industry, turbine construction, motorsports
- Cost of materials: high
Pure titanium (degree 1-4)
- Example of material: degree 2 (3.7035)
- Corrosion protection: high
- Acid resistance: good
- Good mechanical properties (tensile strength)
- Toughness: high even at low temperatures
- Specific density: low
- Thermal conductivity: low
- Not magnetic
- Biocompatibility: excellent
- Machinability: difficult
- Main application areas: medical technology (implants), aerospace industry, watches and jewelry
- Cost of materials: high
The Challenge
The poor heat conductivity is one of the key challenges in all materials made of titanium (pure or alloyed). The heat resulting during the machining process remains on the tool, the cutting edges heat up and the risk of cutting edge breakage is high. Tool life and process reliability suffer because of this.
Nonetheless those who wish to achieve good machining rates cannot avoid the topic of cooling. Cooling is also important since titanium at elevated pressures or at temperatures above 300° (reacts with carbon, oxygen and nitrogen) begins to burn. This risk is even higher when the cooling is interrupted. The high elasticity is an issue especially in pure titanium (degree 1 – 4). It requires a high shearing force and leads to high cutting wear. Chips splinter up and flow only in a viscous and gummy manner. Sharp edges would be appropriate here but this means high wear and a high risk of cutting edge breakage.
The solution
Cooling system
Just like in stainless steels cooling is the key factor that determines success in the machining of titanium. It is the best guarantee that no overheating on the cutting edges takes place. In the "crazy" products from Mikron Tool it is integrated in the tool, whenever possible, either through cooling channels to the drill tip or in the shaft with a coolant outlet on the cone.
Tungsten carbide
The tungsten carbides used by Mikron Tool for the machining of titanium are resistant to thermal shock and at the same time possesses a high degree of bending strength and fracture toughness.
Geometry
The geometry is so designed that no high cutting forces are needed despite the extreme toughness of the material, the tool possesses a high degree of stability and the cutting edges guarantee good chip break with simultaneously good chip removal from the machining area.
Coating
Most products are equipped with a temperature and oxidation-resistant coating that are distinguished by high wear resistance and low adhesion to metals. The micro drill bits for deep holes CrazyDrill Flex are an exception. A coating can be avoided due to its geometry especially geared towards titanium.
Machining process
At Mikron Tool the recommended machining process is always based on the results that were worked out during practical tests. Our goal is always to obtain the best possible ratio of machining time, reliability and tool life. In concrete terms this means the highest possible cutting speeds and feed rates which simultaneously allow proper cooling of the cutting edges and promote continuous chip flow.
The Application Domains
- Aerospace industry: jet engine parts
- Energy equipment: turbine components, impellers
- Medical technology: implants, bone screws, devices
- Dental equipment: implants
- Watchmaking and jewelry industry: watch housing, bracelets
- Chemical industry: pipes and tanks
- Automotive: engine parts and special racing components
Sample applications
Medical technology
- With CrazyDrill Flex Titanium
Suction cannula for eye operations (for example, deep-hole drilling diameter 0.6 mm (.0024”) / 30 mm (1.181”) deep in titanium grade 5, TiAl6V4)
- With CrazyMill Cool
Implant (e.g. milling a bone plate with diameter of 3.5 mm (.138”) in pure titanium, degree 2)
- With CrazyDrill Cool XL
Bone screw (e.g. central hole in the core diameter 2 mm (.0787”) /drilling depth 60 mm (2.362”) in titanium alloy degree 5)
Surgical pincers (e.g. rear deburring head diameter 4.6 mm (.181”) in titanium alloy degree 5)
Dental equipment
Tooth implant (e.g. milling a channel groove with a special milling tool with through-shaft cooling)
Energy equipment/turbine construction
Impeller (e.g. milling diameter 2 mm (.0878”) in titanium grade 5)
Aerospace industry
Landing gear center section (e.g. reaming in different diameters/hole depth 60 mm (2.362”) in titanium degree 6)
Electronics
- With a customer-specific microdrill
Support for optical waveguide (e.g. microholes diameter 0.127 mm (.005”) / drilling depth 1.27 mm (.049”) in titanium alloy grade 5)
The Products
Mikron Tool offers a range of standardized tools that were specially developed for the machining of so-called difficult materials and are suitable for the machining of titanium and titanium alloys. There are also many possibilities of customer-specific tools such as different types of drill bits, step drills, milling bits, reamers, deburring tools, turning tools, form tools and combined tools.
- Centering in the diameter range from 0.3 mm to 6 mm (.0118” to .236”), center tool with through-tool cooling
- Pilot drilling in the diameter range from 0.1 mm to 1.2 mm (.0039” to .0472”), drilling depth 3 x d
- Pilot drilling in the diameter range from 0.4 mm to 6.35 mm (.0157” to .25”), drilling depth 2 x d
- Pilot drilling on inclined surfaces in the diameter range from 0.4 mm to 6.35 mm (.0157” to .25”)
- Drilling in the diameter range from 0.4 mm to 6.35 mm (.0157” to .25”), drilling depth 7 x d
- Deep-hole drilling in the diameter range from 1 mm to 6 mm (.0393” to .236”), drilling depth up to 40 x d, drill with through-tool cooling
- Micro deep-hole drilling in the diameter range from 0.1 mm to 1.2 mm (.0039” to .0472”), drilling depth up to 50 x d, drill with or without through-tool cooling
- Groove, pocket and wall milling in the diameter range from 0.3 mm to 8 mm (.0118” to .315”), milling depth up to 5 x d, milling bits with through-tool cooling
CrazyMill Cool Square & Corner radius
- Copy and side milling in the diameter range from 0.3 mm to 8 mm (.0118” to .315”), milling depth up to 5 x d, milling bits with through-tool cooling
- Plunge directly with up to 1 x d vertically into material, plunge mill in the diameter range from 1 mm to 8 mm (.039” - .315”), milling depths up to 2.5 x d, milling tool with through-tool cooling
- Chamfering and deburring front and rear in the diameter range from 0.4 mm to 6 mm (.0157” to .236”)
- Customer-specific tools in the diameter range from 0.1 mm to 32 mm (.0039” to 1.259”)
Other CrazyLine tools are also suitable for the machining of titanium and titanium alloys depending on the application. Contact us here to know more about these possibilities.