The hardness of titanium alloy is not a fixed value, it will vary greatly according to the specific grade composition and heat treatment process.In the common annealing state, the hardness range is roughly as follows：
Hardness type, typical value range, applicable status / description
Rockwell hardness (HRC) 26-43 HRC This is a common hardness notation and is suitable for most titanium alloys in the annealed state.
Brinell hardness (HB) 250-375 HB is commonly used to describe the hardness of pure titanium or cast titanium alloys.
For reference, the hardness of industrial pure titanium (with more impurities) is about 200-295 HB, and the hardness can be significantly improved after special strengthening treatment.
Examples of specific hardness of different grades
The hardness of different grades of titanium alloys varies significantly. The following are the data of several common grades.：
TC4 (Ti-6Al-4V): This is a common “universal” titanium alloy with a hardness of about 36 HRC in the annealed state.
Industrial pure titanium (Grade 2/TA2): about 195 HB, relatively soft texture and good plasticity.
RT1400 (high-strength β-titanium alloy): After solution aging treatment, the hardness can reach 43 HRC, which is a high-strength level.
Several processes that significantly improve hardness
In addition to the material itself, its surface hardness can be greatly improved through specific surface treatment technologies to meet the needs of wear resistance.：
Carburizing treatment: A hardened layer is formed on the surface by spark discharge, etc., and the surface hardness can soar to 22,000 MPa (the conversion is about 67 HRC or more).
Nitriding/oxygenation treatment: After ordinary thermal oxidation treatment, the surface hardness can reach 16,000 MPa (about 65 HRC).
Laser cladding: The wear-resistant coating is coated on the surface, which significantly improves the local hardness and wear resistance.
Summary: The hardness of conventional titanium alloys is actually higher than that of stainless steel (such as 304 and 316L, which have a solid solution state of about 20 HRC), but it is usually lower than that of quenched carbon steel (up to 50-60 HRC).
