Due to its outstanding corrosion resistance and large specific strength, titanium has great significance in chemical, electricity and aerospace industries as the chief metallic materials for the benefit of their features. In the recent time, titanium has become a popular material for use in the diverse components of cars due to the following aspects:

1. Great demand for lightweight components has considerably decreased the global warning by controlling the emission of carbon dioxide.
2. Significant progress has been observed in the development of technology for the production of economical titanium components
3. The look and modernization of exclusive titanium have attracted the industries.

Heanjia Super-Metals has been setting milestones in producing the titanium products for use in the automobile components. Use of titanium considerably reduces the weight as well as limits the fuel cost in addition of improvement of engine and operation performance. Additionally for larger specific strength as compare to carbon steel, Titanium offers greater heat resistance than aluminum making it fit for use as material to attain the effect of weight loss when the components are subjected to high temperatures above 400oC.

Titanium also offers smaller coefficient of thermal expansion and Young modulus and attains almost half of strain created by thermal expansion and contraction than the ferritic steels. It shows titanium is more beneficial in thermal fatigue characteristic.

Characteristic comparison of Titanium with other materials

Heanjia Super-Metals offers sufficient information for conducting comparison between titanium and traditional heat resistant stainless steel material for employing in the exhaust system. Titanium features good tensile properties at room and high temperature, high fatigue strength, supreme oxidation resistance and thermal fatigue. Its tensile strength at room temperature is equivalent to heat resistant stainless steel for use in exhaust unit that is about 30%.

Titanium accurately performs for mufflers and exhaust pipes. The oxidation temperature of heat resistant stainless steel for an exhaust system is trusted to be up to 850-1050oC. Although titanium is quickly oxidized at temperature up to 700oC that is below the above temperature. However this causes no problem, it is likely that titanium should be oxidation resistant as of heat resistant stainless steel for exhaust units in consideration that this oxidation temperature limit will be higher because of need of a larger output and legalization to govern exhaust gas.

Titanium receives adequate surface treatment by surface conditioning like atmospheric oxidation that adds value in this metal considering the design.

Applications

Titanium’s application began with aftermarket of major sized motorcycle in 1997, finalizing in mounting on mass based large size motorcycles. However four-wheeled vehicles utilizing titanium components are usually observed in the aftermarket, the influence of weight loss and suitable design has increased the application of titanium in the latest car models.

Engine valves

The weight saving in engine component is more suitable than that of other components considering the enhanced fuel consumption, reduced noise emission and larger power efficiency. In specific, the effect is considerable in engine valves and use of titanium is can be made maximum.

Intake valves

Titanium in intake valves is used in the various models of motorcycles and four-wheeled automotives. It is used in intake valves for the quick requirement of becoming lightweight and larger efficiency.

The complications in the implementation of titanium are to develop the wear resistant surface treatment as this metal is prone to wear. Surface processing such as TiN coating, molybdenum spray coating and chromium plating is done in the standard cases. Although these methods are expensive and are found unfit in sustaining the prolong wear resistance. Following this, it was confirmed to use oxidizing treatment using solid solution hardening of oxygen, a processing featured by developing a comparative thick hardened layer.

The oxidizing treatment is normally a heat processing to heat the metal at high temperature in air. It is essential, although to avoid the valve from being deformed by self-weight while oxidizing processing, as the creep resistance of titanium is not satisfactory at the elevated temperature. It is found feasible to prevent the damage during heat processing by changing the structure completely into an acicular microstructure.

The acicular microstructure is normally supposed to be lower in ductility and fatigue strength. It is feasible to protect the high ductility and fatigue resistance similar to those of equiaxed by changing completely into acicular microstructure without permitting the coarse phase to precipitate with the alpha grain boundaries. Generally wear resistance increases when an oxygen hardened layer is offered, whereas fatigue strength is found to reduce when oxygen hardened layer is offered. In this way, titanium is made fit for use in the applications demanding high wear resistance.