What are the advantages and disadvantages of titanium alloy?

1 has high strength, and the density of titanium alloy is generally around 4.5 1g/ cm3, which is only 60% of steel. The density of pure titanium is close to that of ordinary steel, and the strength of some high-strength titanium alloys exceeds that of many alloy structural steels.

2. The thermal strength is high, the service temperature is several hundred degrees higher than that of aluminum alloy, the required strength can still be maintained at moderate temperature, and it can work for a long time at 450 ~ 500℃. These two kinds of titanium alloys still have high specific strength in the range of 150℃ ~ 500℃, while the specific strength of aluminum alloys decreases obviously at 150℃. The working temperature of titanium alloy can reach 500℃, while that of aluminum alloy is below 200℃.

3, the corrosion resistance is good, titanium alloy works in humid atmosphere and seawater medium, and the corrosion resistance is far better than that of stainless steel; Especially strong resistance to pitting corrosion, acid corrosion and stress corrosion; Excellent corrosion resistance to alkali, chloride, chlorine, nitric acid, sulfuric acid and other organic substances. However, the corrosion resistance of titanium to reducing oxygen and chromium salt medium is poor.

4, the low temperature performance is good, and the titanium alloy can still maintain its mechanical properties at low temperature and ultra-low temperature. Titanium alloys, such as TA7, which have good low temperature performance and extremely low interstitial elements, can still maintain certain plasticity at -253℃. Therefore, titanium alloy is also an important low-temperature structural material.

5. High chemical activity, high chemical activity of titanium, and strong chemical reaction with O, N, H, CO, CO2, water vapor, ammonia and so on in the atmosphere.

6. The thermal conductivity is very small. The thermal conductivity λ =15.24 w/(m k) of titanium is about 1/4 of nickel, 1/5 of iron and114 of aluminum, while the thermal conductivity of various titanium alloys is about 50% lower than that of titanium.

Second, shortcomings.

The main limitation of 1, titanium and titanium alloys is their poor chemical reactivity with other materials at high temperature. This characteristic forces titanium alloy to be different from traditional refining, smelting and casting processes, and even often causes mold damage.

2. The price of titanium alloy becomes very expensive. So at first, it was mostly used in aircraft structure, aircraft, and high-tech industries such as petroleum and chemical industry.

Baidu encyclopedia-titanium alloy