1、 Physical characteristics
1. Lightweight advantage
The density is 4.51g/cm ³, which is only 57% of steel and has the highest specific strength among industrial alloys. It is suitable for weight reduction scenarios such as aerospace and consumer electronics.
Typical application: The proportion of titanium alloy used in C919 aircraft is 15%, and the weight of the titanium alloy frame in foldable screen mobile phones is reduced by 30%.
2. Low thermal conductivity
The thermal conductivity is only 1/5 of steel, and heat is prone to accumulate during cutting, causing the tool to overheat. High pressure cooling technology is needed to alleviate this issue.
2、 Mechanical properties
1. High strength and toughness
The tensile strength reaches 686-1176MPa, and the high-temperature alloy maintains a creep resistance of over 300MPa at 550-600 ℃.
Excellent low-temperature performance: suitable for extreme environments such as liquid hydrogen storage tanks.
2. Low elastic modulus
The elastic modulus is approximately 1.078 × 10 ⁴ -1.176 × 10 ⁴ MPa, which is half that of steel. When processing thin-walled parts, it is prone to deformation and requires optimization of clamping rigidity.
3、 Environmental adaptability
1. Corrosion resistance
The surface oxide film (TiO ₂) self repairs in oxidizing media and has better corrosion resistance to seawater and acid mist than stainless steel. The hydrogen permeability of the bipolar plate in hydrogen fuel cells is less than 1 × 10 ⁻¹ ² cm ²/s.
2. Temperature resistance performance
Long term temperature resistance up to 600 ℃, short-term ability to withstand extreme environments up to 2000 ℃.
3. Resistance to hydrogen embrittlement
Ti-0.2Pd (TA9) and other alloys have outstanding resistance to hydrogen permeation in nuclear reactor coolant, avoiding brittle fracture.
4、 Processing characteristics
1. Cutting difficulties
High chemical activity, easy to bond and wear with cutting tools, YG type hard alloy cutting tools should be selected and the cutting speed should be controlled to be less than 60m/min.
The work hardening tendency is significant, and the layered cutting strategy can reduce surface residual stress.
2. Plastic deformation characteristics
Hot processing needs to be carried out above the β phase transition point, while cold processing requires interlayer annealing to eliminate residual stress.
Summary: Titanium processed parts continue to expand their application boundaries in the high-end manufacturing field through material design and process optimization.