GENERAL CHARACTERISTICS OF DLC

As mentioned in Chs. 12 and 13, a new form of csufxm coeiting is now available which is neither diamond nor graphite and is known as diamondlike carbon (DLC). The term DLC was introduced in 1973 by Aisenberg, a pioneer in this fieid.hl 

DLC can be considered as a metastable carbon produced as a thin coating with a broad range of structures (primarily amorphous with variable sp /sp bonding ratio) and compositions (variable hydrogen concentration) DLC coatings alter the surface properties of a substrate in a manner similar to that of CVD diamond (see Table 13.2, Ch. 13). 

As opposed to diamond which occurs naturally and can be synthesized at both high and low pressure, DLC is not a natural material and can only be produced at low pressure. DLC has two disadvantages low deposition rate and high internal stress. Unlike diamond, it cannot be obtained as thick monolithic shapes, at least with the present technology. 

However, DLC has properties similar to CVD diamond and it is easier to process without the high-temperature substrate requirements and with little restriction on size. A number of important applications have been developed with a promising future. 

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