我国汽车行业与国际同行的差距主要在于发动机关键零部件的摩擦磨损。类金刚石（DLC）碳膜技术是解决发动机关键零部件摩擦磨损问题的有效途径，但传统的DLC碳膜在制备过程中会产生较高的内应力（可达10GPa）,从而导致薄膜失效。首先分析了DLC碳膜在汽车零部件领域的应用背景，探讨了薄膜内应力的来源，重点综述了异质元素掺杂降低类金刚石碳膜内应力的研究现状。常用掺杂元素按化学性质可分为碳化物形成元素与非碳化物形成元素，不同于其他分类方法，笔者按掺杂元素的组元多少进行划分，从单元掺杂、二元或多元掺杂入手，系统分析了各种掺杂方式、掺杂元素的优缺点。在此基础上，指出元素掺杂降低类金刚石碳膜内应力的研究从最初的单一元素掺杂，逐步发展到了二元或多元元素掺杂；从碳化物形成元素掺杂、非碳化物形成元素掺杂，逐步发展到碳化物形成元素与非碳化物形成元素的多元共掺杂；所研究的类金刚石碳膜的显微结构也从最初的非晶态结构向多元、多相结构发展，以期获得良好的综合机械性能。

Tribological properties of key engine components show the big gap between domestic automotive industry and international counterpart. Diamond-like carbon (DLC) coating technique can effectively over come tribological problem of key engine components. Usually, high internal residual stress (up to 10 GPa) generate din deposition process will lead to failure of pure DLC coatings. Application background of DLC coatings in the field of automotive components was analyzed firstly, origin of internal stress in DLC coatings was discussed, and research status of internal stress reduction in DLC coatings by elemental doping was reviewed emphatically. Common doping elements could be classified into carbide forming elements and non-carbide forming elements on the basis of chemical property. However, the elements in this paper were classified according to constituent elements of doping elements instead of other approaches. Advantages and disadvantages of various doping methods and doping elements were analyzed systematically by starting with single- and multi- element doping. On this basis, it was pointed out that objects of studies on internal stress reduction in DLC coatings by elemental doping developed from single element in the beginning into multi-element doping gradually; and from carbide forming elements and non-carbide forming elements into multi-element co-doping of carbide forming elements and non-carbide forming elements. Microstructure of studied DLC coatings developed from amorphous structure into multi-element and multiphase structures, so as to obtain better comprehensive mechanical properties.