Customize Lightweight CNC TC4 Titanium Turned Small Parts For Bluetooth Controller
Titanium and its alloys are known to us for their high strength, durability and corrosion resistance. It is widely used in the aerospace and medical industry. We have benefited a lot from titanium parts, but there are still many limitations in titanium CNC machining. This article will discuss what is titanium, common titanium alloys, and titanium CNC machining.
What is Titanium?
Titanium is a metal element. The atomic number of titanium in the periodic table of elements is 22 (4th period, NB group). It has a silver-white metallic luster and has many excellent properties such as high melting point, low density, high strength, and good flexibility. It is important for industrial materials.
Commercially Pure Titanium
Commercially pure titanium contains a minimum of 99% pure titanium. Four commercially pure types of titanium, namely Grades 1 – 4.
Grade 1: The softest and most ductile of these grades. It possesses the greatest formability, excellent corrosion resistance, and high impact toughness.
Grade 2: It shares many of the same qualities as Grade 1 titanium, but it is slightly stronger.
Grade 3: It is stronger than Grades 1 and 2, similar in ductility, and only slightly less formable.
Grade 4: The strongest of the four grades. It possesses corrosion resistance, good formability, and weldability.
Mechanical properties of commercially pure titanium
Property | Grade 1 | Grade 2 | Grade 3 | Grade 4 |
Tensile Strength (MPa) | 240 | 345 | 450 | 550 |
Yield Strength (MPa) | 310 | 450 | 550 | 655 |
Elongation at break(%) | 24 | 20 | 18 | 15 |
Why is Titanium Difficult To Process?
Titanium alloy has the advantages of being lightweight and high strength. However, the difficulty of processing titanium alloy has always troubled engineers and technicians.
Low heat conductivity. Most titanium alloys have extremely low thermal conductivity, which is only 1/7 of steel, 1/16 of aluminum, and 1/25 of copper. Therefore, the heat generated during cutting materials is not easy to dissipate and is concentrated in the cutting area. This can easily lead to rapid wear and cracking of the tool and generate chip accumulation, shortening the tool’s life.
Elastic deformation of titanium. The elastic modulus of titanium alloy is relatively low. For example, the elastic modulus of TC4 is only 110 GPa, while that of 45 steel is 210 GPa, and that of 303, 304, 316, and other stainless steels is also around 200 GPa. When machining titanium alloy, elastic deformation is easy to occur, especially when machining thin-walled or annular parts.
Vibration. The elasticity of titanium alloys may be beneficial from part performance, but it becomes the main cause of vibration during cutting. The vibration generated by machining titanium alloys is 10 times that of steel. Since the cutting heat is concentrated in the cutting part, it will produce zigzag chips, causing cutting power fluctuations.