Titanium-the rising third metal's characteristics and applications

Compared to other metal materials, titanium may be a stranger to you. Titanium, named after Titan in Greek mythology, is a chemical element, chemical symbol Ti, is a silver-white transition metal. Titanium is recognized as a non-toxic element in the world, and is the special material for NASA's rocket satellite of the same type, which has been applied to China's Jade Rabbit, J-20, Shandong aircraft carrier and other super projects.  

What are the specific properties of titanium?  

Advantages of titanium:  

1. Low density, high strength, high specific strength  

The density of titanium is 4.51g/cm3, 57% of steel, just a little more than half of steel, less than two times of aluminum, strength is three times than aluminum, titanium alloy specific strength is commonly used in the largest industrial alloy, titanium alloy specific strength is 3.5 times of stainless steel, is 1.3 times of aluminum alloy, is 1.7 times of magnesium alloy.  Application examples: tennis racket, badminton racket, golf ball head, club, eyeglass frame, etc., are the applications of their characteristics of low density, light weight and high strength.

2. Excellent corrosion resistance  

The dullness of titanium depends on the presence of oxide film, and its corrosion resistance is much better in oxidizing media than in reducing media, where high rates of corrosion can occur.  Titanium is not corroded in some corrosive media, such as seawater, wet chlorine, chlorite and hypochlorite solution, nitric acid, chromic acid, metal chloride, sulfide and organic acids.  Application example: Titanium pot for cooking, there are often weak acid, weak alkali, salt and other corrosive environment in daily life, titanium has good corrosion resistance, and will not rust.  

3. Good heat resistance  

Usually aluminum at 150℃, stainless steel at 310℃ that is lost the original high mechanical properties, and titanium alloy at about 500℃ still maintain good mechanical properties.  Titanium has good heat resistance and is suitable for turbine discs and blades of aero-engine compressors and skin of the rear fuselage of aircraft.  Application example: Titanium pot in the process of fire cooking, excellent heat resistance.  

4. Non-magnetic, non-toxic  

Titanium is a non-magnetic metal, will not be magnetized in a large magnetic field, non-toxic and has a good compatibility with human tissues and blood.  Application examples: titanium tableware, water ware, cooking ware and so on are designed and manufactured because titanium is non-toxic to human body and no metal precipitation.  

5. Small thermal conductivity  

Titanium has a small thermal conductivity, only 1/5 of steel, 1/13 of aluminum, and 1/25 of copper.  

6. Elastic modulus 

The elastic modulus of small titanium is about 55% of iron.  

7. Low damping performance  

The performance of titanium can be used as tuning fork, vibration element of medical ultrasonic crusher and vibration film of advanced loudspeaker.  

Disadvantages of titanium:  

1. High cost, the price of titanium is 5-10 times that of stainless steel.  

2. The processing is difficult, because titanium is an active metal, the processing environment is more demanding than stainless steel.  

3. Poor thermal conductivity, easy to paste and stick the pot in the pot, but in the thermos cup can improve the thermal insulation effect.  

4. Compared with stainless steel, the surface hardness of pure titanium is about HRC20, stainless steel can usually reach HRC56-58, easier to scratch in the process of use.  

5. Poor polishing performance, titanium in the polishing process is more sticky, mirror polishing is more difficult than stainless steel.  

6. Compared with copper and stainless steel, the surface of titanium is easier to leave fingerprints and difficult to remove.