HB350 hardness greater than titanium machining particularly difficult, less than HB300 is prone to stick a knife phenomenon, but also difficult to cut. However, only one aspect of the hardness of titanium machining difficult, the key is the combined effect of its machinability of chemical, physical and mechanical properties of titanium itself between. Cutting Titanium has the following characteristics:
(1) deformation coefficient is small: This is a significant feature of titanium machining, deformation coefficient is less than or close to one. Chip away the knife sliding friction surface greatly increases the previous accelerated tool wear.
(2) high cutting temperatures: As low thermal conductivity of titanium alloy (equivalent to only 1/5 ~ 1/7 45 steel), the contact length of the chip and the rake is very short, the heat generated when cutting difficult to pass out, concentrated in a smaller range of the cutting area and near the cutting edge, high cutting temperatures. Under the same cutting conditions, the cutting temperature higher than 45 steel cutting more than doubled.
All countries in the development of new low-cost and high-performance titanium reducer, titanium alloy into the civilian efforts to make positive industry has huge market potential. New progress of titanium alloy is mainly reflected in the high temperature titanium alloy.
Successfully developed the world's first high-temperature titanium alloy is Ti-6Al-4V, using a temperature of 300-350 ℃. Then have developed a use temperature of 400 ℃ of IMI550, BT3-1 and other alloys, as well as the use of a temperature of 450 ~ 500 ℃ of IMI679, IMI685, Ti-6246, Ti-6242 alloy. Has been successfully applied in military and civil aircraft engines in the new high-temperature titanium alloys have British IMI829, IMI834 alloys; United States of Ti-1100 alloy; Russia BT18Y, BT36 alloy. Table 7 for the highest temperature part of the country's new high-temperature titanium alloy.
In recent years, the use of foreign fast solidification / powder metallurgy technology, fiber or particle-reinforced composites developed high temperature titanium alloy as the development direction, so that the use of temperature titanium alloy can be increased to more than 650 ℃ [1,27,29,31 ]. American McDonnell Douglas by rapid solidification / powder metallurgy technology has successfully developed a high-purity, high-density alloy, its strength at 760 ℃ ambient temperature is equivalent to the intensity of use of titanium
All countries in the development of new low-cost and high-performance titanium, titanium hollow bar into the civilian efforts to make positive industry has huge market potential. New progress of titanium alloy is mainly reflected in the high temperature titanium alloy.
Successfully developed the world's first high-temperature titanium alloy is Ti-6Al-4V, using a temperature of 300-350 ℃. Then have developed a use temperature of 400 ℃ of IMI550, BT3-1 and other alloys, as well as the use of a temperature of 450 ~ 500 ℃ of IMI679, IMI685, Ti-6246, Ti-6242 alloy. Has been successfully applied in military and civil aircraft engines in the new high-temperature titanium alloys have British IMI829, IMI834 alloys; United States of Ti-1100 alloy; Russia BT18Y, BT36 alloy. Table 7 for the highest temperature part of the country's new high-temperature titanium alloy.
In recent years, the use of foreign fast solidification / powder metallurgy technology, fiber or particle-reinforced composites developed high temperature titanium alloy as the development direction, so that the use of temperature titanium alloy can be increased to more than 650 ℃ [1,27,29,31 ]. American McDonnell Douglas by rapid solidification / powder metallurgy technology has successfully developed a high-purity, high-density alloy, its strength at 760 ℃ ambient temperature is equivalent to the intensity of use of titanium
The use of titanium in the car two main categories, the first category is used to reduce the quality of internal combustion reciprocating member (for reciprocating internal combustion engine parts in terms of reducing even a few grams of quality are important); the second category is used to reduce the total mass of the car. According to the design and the material properties of titanium bar on the new generation of vehicles mainly in the engine components and chassis components. In the engine system, can produce titanium valves, valve springs, valve springs and connecting rod bearing and other components; chassis components primarily for springs, exhaust system, axle and fasteners.
According to information, in addition to the above cited focus, there are: Rocker engine parts, suspension springs, piston pin, turbocharger rotor, fasteners, lug nuts, bumper brackets, door broke into the beam, brake caliper piston, the pin bolt, the clutch disc, the pressure plate, the shift button, and so on.
Titanium applications and features in the car
Titanium is a new structural and functional materials, it has excellent overall performance, density, high specific strength. Higher than the strength of the titanium plate alloy aluminum and steel, toughness and steel quite. Titanium and titanium alloy corrosion performance is good, better than stainless steel, particularly resistant to corrosion and micro-oxidizing atmosphere under chloride ion corrosion resistance in the marine atmosphere, a wide operating temperature titanium alloys, titanium alloys at low temperature -253 ℃ but also to maintain good ductility, and heat-resistant alloy operating temperature up to about 550 ℃, its heat resistance was significantly higher than that of aluminum and magnesium alloys. Also has good workability, weldability.
Titanium and titanium alloy Ti excellent performance since the industrial production on various tech industries much attention, along with the titanium bolts industry started in the mid-1950s, titanium into the automotive industry. Into the 1990s, with the worldwide shortage of energy and enhance the awareness of environmental protection, especially in the automotive industry, the US, Japan and Europe and other countries have issued a series of ecological regulations on fuel efficiency, CO2 emissions, vehicle weight, automobile safety, reliability and put forward higher requirements. Many developed countries and the famous car manufacturers are actively developing and increasing investment in automotive research titanium. Provided a powerful impetus for the car with titanium.
Application of titanium in life
Advanced technology and methods of powder metallurgy as a modern metallurgy and materials processing in the titanium sheet industry has played an important role. Titanium powder metallurgy nearly molding technology, direct preparation of finished or nearly finished size of components, reducing the consumption of raw materials, shorten the processing cycle, cost savings of 20% to 50% compared with conventional processes. In the automotive industry, titanium powder metallurgy particular attention in recent molding technology in Japan, powder metallurgy parts are widely used in automobile engines and transmissions, which, connecting rods, valve seats, valve, the pulley, the synchronizer hub, synchronizing rings so are complex and demanding critical parts. Zhu titanium powder metallurgy current research is in the stage of rapid development, including a child, first, high-quality low-cost titanium powders were prepared by technology and its industrialization; the second is the preparation of titanium plate powder metallurgy technology even while in the automotive industry promotion applications.
One reason for the high price of titanium alloying elements is higher prices.
With the progress of titanium smelting technology, the rear titanium investment casting production process generated Scrap, scrap and other salvage treatment after the series as the charge added to achieve the production cycle, is an effective way to reduce the cost of raw materials. Practice shows that for every 1% of residual use of titanium, titanium ingot can reduce production costs by 0.8%. If the electron beam cooling bed furnace, plasma beam cooling bed furnace smelting, can not only improve the quality of titanium ingot metallurgy, while extensive use of recycled scrap, ingot reduce costs.
Reduce processing costs
More than 60% of the total cost of processing costs for countries to reduce the cost of key research. titanium tubing components in the production process of the production process is not only complex, but generated a lot of residual titanium in the production process, and a longer production cycle, resulting in parts production costs. Hinders its broader application.
Casting is a classic (nearly) net molding process. Production of parts without machining or machining rarely, thus saving a lot of metal. Casting can often produce a complex shape parts, and these parts are made of other conventional process for the manufacture of complex, high production costs, especially for the relatively high price of materials titanium. Currently, a large number of applications in the aerospace industry titanium castings. In the automotive industry, the production of parts by casting method has a valve, turbo pressure, etc. zo.
