2002 Volume 53 Issue 9 Pages 606-611
The scratching properties of DLC films containing various metals such as titanium, molybdenum and iron were investigated. These films were deposited on Si substrate by using magnetron radio frequency sputtering. High pure metal/graphite combined plates having area ratios of 1/8, 1/16 and 1/32, were used as targets in order to change the metal content of the film. The properties of the film were examined by means of a nano-indentation hardness tester utilizing an atomic force microscope, and an oscillating type scratch tester with simultaneous AE detecting.
The main results are summarized as follows: (1) DLC films containing titanium and molybdenum show larger nano-indentation hardness on the average than that of DLC film without metal. In particular, titanium is an effective element to get higher hardness. On the other hand, iron contained DLC film shows lower hardness. (2) The critical loads on the scratch test are affected by species and contents of metals. Especially, the load of titanium contained DLC film deposited by using a target of 1/16 is nearly two times larger than that of DLC film without metal. (3) Observation showed that many parts of the DLC film without metal wave damaged during scratching, however, there were no damaged parts for titanium contained film due to a higher adhesive strength. (4) Addition of titanium to a DLC film tends to increase the fracture size of the film in the scratching due to enhancement of the films rigidity, and increase the films hardness.
