Titanium is a new type of metal, and its properties are related to the impurity content of carbon, nitrogen, hydrogen, oxygen, etc. The purest titanium iodide impurity content does not exceed 0.1%, but its strength is low and its plasticity is high.
performance high strength
Some titanium alloys are harder than many types of steel. Thus, the titanium alloy can be designed to develop products with high strength, good rigidity and light weight because the engineering strength (strength/density) of titanium alloy is higher comparitively than other metallic structural materials. The aircraft's engine parts, frame, skin, fasteners and landing gear are all constructed from titanium alloy.
High thermal intensity The use temperature is several hundred degrees higher than that of aluminum alloy, and it can still maintain the required strength at moderate temperatures.It can be used for a long time at 450–500 ℃. Two aforementioned titanium alloys can keep very high specific strength within 150 ∼ 500 ℃, while this metal drastically lost its specific strength at 150 ℃. The working temperature for titanium alloy is up to 500 ℃ while the working temperature for alumimun alloy is less than 200 ℃.
Good corrosion resistance
Performance testing of "titanium" alloy to see its corrosion resistance, what exactly is it? | Military Technology Titanium alloys work in humid atmospheres and seawater media, and their corrosion resistance is much better than stainless steel; Has particularly strong resistance to pitting corrosion, acid corrosion, and stress corrosion; Has excellent corrosion resistance to alkali, chloride, organic substances such as chlorine, nitric acid, sulfuric acid, etc. However, titanium has poor corrosion resistance to reducing oxygen and chromium salt media.
Good low-temperature performance
The mechanical properties of titanium alloys can be retained at low and ultra-low temperatures. good low-temperature performance, extremely low interstitial element titanium alloy such as TA7 has some plasticity even at -253 ℃. Consequently, the titanium alloy is also considered as key low temperature structural material. Despite the high performance of titanium alloy components, the large-scale application of titanium and its alloys in the automotive industry is still a long way off, because of the problems of high cost, bad formability, and poor welding performance. The principal barrier to wider use of titanium alloys for automotive applications is cost. A primary limitation of titanium and titanium alloys is the difficulty tochemically react with other materials at high temperatures.
High chemical activity Titanium has high chemical activity, and at temperatures above 600 ℃, it absorbs oxygen to form a hardened layer with high hardness; An increase in hydrogen content can also form a brittle layer. The hard and brittle surface layer generated by gas absorption can reach a depth of 0.1-0.15 mm, with a hardening degree of 20% -30%. Titanium has a high chemical affinity and is prone to adhesion with friction surfaces. Low thermal conductivity and elasticity The thermal conductivity of titanium, λ=15.24W/(m · K), is about 1/4 that of nickel, 1/5 that of iron, and 1/14 that of aluminum. However, the thermal conductivity of various titanium alloys is about 50% lower than that of titanium. The elastic modulus of titanium alloy is about half of that of steel, so it has poor rigidity and is prone to deformation. It is not suitable for making slender rods and thin-walled parts. During cutting, the springback of the machined surface is large, about 2-3 times that of stainless steel, causing severe friction, adhesion, and bonding wear on the back surface of the tool.
An excellent performance for the components of titanium alloy, but this is still a long way to for the popularization of the automobile of titanium and its alloys in the automotive industry, because of high cost, poor plasticity, poor welding due to such reasons.Titanium alloys are among the strongest and lightest metals but are also expensive and traditionally hard to produce in large quantities.The main barrier to the use of titanium alloys more widely in the automobile industry is their expense. The chief limitation to the use of titanium and its alloys has been the ease with which they can undergo chemical attack, preferentially with other materials (overcoated, e.g., by ceramic thermal protection materials) but especially in air and water at high temperatures.
This property forces titanium alloys to be different from traditional refining, melting, and casting techniques, and often causes damage to molds; As a result, the price of titanium alloy has become very expensive. Therefore, they were initially mostly used in aircraft structures, aircraft, and high-tech industries such as petroleum and chemical industries.
