In China, because of the late start of titanium alloy research, the application of titanium alloy is very limited, which greatly restricts the development of titanium alloy technology.At present, the research depth and breadth of titanium alloy are not enough, let alone the scale of application.At present, it is only limited to two-phase titanium alloy, and there is still a broad space for research.With the continuous development of titanium industry, titanium alloy will receive more and more attention. It is believed that in the near future, titanium alloy will be successfully applied in the production of important parts of titanium alloy.
Application prospect of civil titanium materials.At present, powder metallurgy titanium alloy has begun to be applied in new high-performance vehicles, mainly used in the engine system and chassis, such as in the engine system with titanium alloy instead of alloy steel and stainless steel into valves, valve springs and connecting rod and other parts;Mainly used in the chassis spring, exhaust system, half shaft and various fasteners.Japanese Toyota motor corporation has developed a method of powder metallurgy forging which can effectively reduce the cost.The weight of titanium valve in automobile engine can be reduced by 40%.The intake valve is made of ti-6 al-4v alloy through powder metallurgy forging process, and the exhaust valve is made of composite material. The composite material adopts a new alloy powder processed with boride as the intensifier, and the volume fraction of TiB strengthened powder is about 5%.The matrix composition is ti-6al-4sn-4zn-1mo-0.2si-0.3o. This composite material has excellent creep resistance.
The benefits of titanium in automobile application are self-evident, which can greatly reduce the quality, reduce fuel consumption, improve work efficiency, improve the environment and reduce noise. The key is how to reduce the cost of titanium and its alloy parts to an acceptable level.According to the study, if the traditional production technology is adopted, the cost of rolling titanium products is 4.4usd /kg. According to the general experience, the cost of each processing step should be doubled, so the cost of materials should reach at least 17.6usd /kg.Rolled products cost up to 44USD/kg after being made into the final machined parts.Obviously, it is impossible to replace the corresponding steel parts with such titanium.Titanium using powder metallurgy, however, is quite different.If the current available price of titanium sponge fine powder or residual material is 4.4~8.8USD/kg, then the cost of the blank will be lower than 4.4USD/kg.After the minimum amount of cutting, the cost of connecting rod and other parts is 8.8~11USD/kg.Powder metallurgy can not only use low-cost raw materials, but also reduce the cost of mechanical processing, especially the net shape or near net shape method is an effective way to produce larger size and lower price auto parts.Visible, powder metallurgy titanium material has a strong competitiveness.
Titanium alloy TC5: stable below 350, plastic decline at higher temperature.In the hot state can be forged, stamping and other deformation under 350℃ work parts.Titanium alloy TC9: thermoplasticity is good.The machinability is the same as TC4 alloy.High corrosion resistance.Good thermal stability under 400℃ long - term working parts.Compressor disc and blade can be made.Titanium alloy TC10: poor stamping, good thermoplasticity.Various forms of welding, welding joint strength up to 90% of the strength of the matrix metal.The machining properties of TC4 alloy are the same.Good corrosion resistance.Good thermal stability, heat treatment effect is significant, hardenability good to do below 450℃ long-term work parts.
Compared with the traditional trial-and-error method, adopting simulation technology as a research and development method can shorten the research cycle, reduce the production cost and optimize the production process, so as to improve the production efficiency and increase the economic benefits.Due to its high price and long production cycle, the study of titanium alloy production process urgently needs simulation technology to open up a shortcut for it and overcome the difficult problems such as narrow temperature range of hot processing, complex and diverse relationship between technology, microstructure and performance.Thermal simulation technology and numerical simulation technology have been used to study the thermal deformation mechanism and microstructure evolution of titanium alloy at home and abroad.However, due to the inaccuracy of material performance data, the difficulty in getting the boundary conditions and friction parameters close to the actual situation, and the fact that the study of macro variables does not involve the change of microstructure, the simulation results have some errors compared with the actual production.Future titanium alloy thermal deformation mechanism and microstructure evolution law of research should be the organic combination of the physical simulation and numerical simulation technology to establish the finite element model of macroscopic more in line with the actual production process, with the microstructure evolution model coupling, makes every effort to the simulation results not only provide theoretical basis for the production, but also can guide field quantitatively process, ultimately achieve real-time tracking deformation process, control the purpose of product quality.