In recent years, due to environmental problems, not only is the four wheel vehicle (car), the two wheeled vehicle (motorcycle or discount car) has been formulated strict rules, and it is popular in the worldwide. The technology requirements of low emission and low fuel cost of wholesale car are also getting higher and higher. However, the previous mentioned low emission, low noise is always related to the problem of high output engine.
The features of titanium material used as automobile parts materials are as follows: high tensile strength and yield strength, high fatigue strength, large small density, elastic modulus is about half of steel, low coefficient of thermal expansion, it is about half of stainless steel and aluminum materials, non magnetic, low thermal conductivity, easy to produce sintering, no pollution to environment. In addition, in the automotive industry with titanium, the vehicle weight can be greatly reduced, the fuel consumption can be reduced, environment can be protected and the noise will be reduced.
In recent years, the automobile companies have engine valve for the development of cheap titanium material, and a part of mass has been reached. The manufacturing cost of titanium material in accounting for above 1/3 is the price of titanium sponge. If we use substandard production of sponge titanium to produce the processing materials, so the price will be naturally reduced. In this case, the cheap Ti-6Al-4V titanium alloy was developed. Even though, we use the blank manufacturing valves, we should also be based in order to reduce the cost. Generally speaking, forging blank of valve upsetting the umbrella, with wire diameter slightly the same shaft. But in the manufacture of wire, to repeat the rolling, wire drawing, annealing process, then the removal of the surface oxide layer, so that the yield of material is not good, the price is higher compared with the bar. This refers to the valve which adopts a cheap bar, and the forging billet is used in extrusion forging method.
