In nature materials, diamond has a unique and irreplaceable special multifunctional material, which has excellent mechanical properties, thermal properties, light transmittance, longitudinal wave velocity, semiconductor properties and chemical inertia. The growth of diamond films grown by chemical vapor deposition (Vapor Deposition Chemical CVD) is almost the same as that of granular natural diamond and high pressure synthetic diamond, but it has overcome the limitation of the size of the small granular natural diamond and high pressure diamond. Materials scientists agree that only the continuous large size of the bulk material, in order to make the full use of the diamond all excellent performance. The excellent properties of diamond films are mainly shown in the following aspects:
Diamond in the known material of the highest hardness (Vivtorinox hardness of up to 10400kg/mm2 this site note: about 102GPa), the best wear resistance and low friction coefficient. CVD diamond film does not contain any binder, the crystal structure of the has almost the same hardness in all directions and no cleavage plane, so the comprehensive mechanical properties of both the advantages of single crystal diamond and polycrystalline diamond (PCD), and in a certain extent and overcome the lack of it, and the price is low. It not only can substitute for the natural diamond, high pressure synthetic single crystal diamond and polycrystalline diamond (PCD) in the field of mechanical application and greatly broaden the scope of its application: such as the manufacture of a variety of suitable for soft and hard drawn wire high performance wire drawing die; welding type of CVD diamond tool (service life more than 1-3 times of PCD tools); making complex shape of CVD diamond coated cemented carbide tool (service life of 10-50 times higher than before the coating); the low friction coefficient can also be for friction parts such as bearing wear resistant coating. According to foreign experts, only applied to the ultra hard materials can be developed, and more than two thousand kinds of new products.
Diamond in all materials in the sound velocity of the fastest, 18.2km/s. Using this performance can not only make the frequency response over 5GHz surface acoustic wave devices (the high-frequency sound surface wave device in the field of communication application is extremely extensive) but also making frequency response up to more than 60 kHz ultra high fidelity speakers and properties of the most excellent acoustic sensor.
The thermal conductivity of natural diamond is 20W/cm.K, which is 4 times higher than SiC, 13 times higher than Si, 43 times higher than GaAs, times of Cu and 4-5 times of Ag, high purity CVD diamond film has reached even more than that of natural diamond film. CVD diamond film heat sink a large number of applications will cause a huge change in the electronic industry.
CVD diamond films are highly permeable and can be used in harsh environment, such as high transmittance, high temperature resistance, corrosion resistance, mechanical strength and so on. Such as the high speed interceptor missile head cover and the application of a wide range of infrared detectors, infrared focal plane array thermal imaging device window, high power microwave window, high power laser window, etc., transparent X optical properties can be used as an ideal material for submicron optical lithography. Excellent optical performance and low price makes the CVD diamond films have a wide range of applications in both military and civilian optical fields.
Electrical and semiconductor properties:
CVD diamond film with excellent electrical characteristics, can be used for high temperature, high power, high frequency, strong radiation environment of electronic devices and various characteristics of the sensor, etc.. Its cold cathode emission characteristics, has the potential to obtain low power, high clarity, ultra-thin, ultra large screen color display. The most promising high temperature semiconductor device operating temperature can reach 600 degrees, the advent of high temperature semiconductor devices, will be a revolution in electronic technology.
At room temperature, alkali and acid resistant to all solvent, even at high temperature, anti acid corrosion of all. Can be seen that the diamond is extremely stable, can be used as an anti corrosion protective layer. In the field of medical devices, because of the extremely sharp knife and the human blood is not compatible with the human blood, the operation effect is good, the patient recovered quickly, CVD diamond cutter will replace the current use of metal surgical instruments; CVD diamond film is pure carbon element and wear resistance, corrosion resistance is the best coating of metal elements in the human body.
CVD diamond films are widely used in mechanical, thermal, optical, acoustic, electronic, aerospace and other fields will have a revolutionary impact on these areas. As a result, the CVD diamond film material is considered as the material in twenty-first Century, "the age of the diamond film has been exposed".