| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 90 === The main purpose of this study is to research the tribological properties and turning performance of titanium hydrogen-free amorphous carbon coatings prepared by sputtering graphite and titanium targets with a medium frequency Twin magnetron sputtering and unbalanced magnetron sputtering hybrid system.
It contains two stages of research in the study. We focus the influence of substrate bias on the properties of coatings in first stage. We change the current of titanium target to get various titanium quantities of coatings in second stage. Finally, a dry turning of coated inserts will be undergone to understand the turning performance of titanium hydrogen-free amorphous carbon coatings.
Through the research of the first stage we know that the hardness of the coatings increase and the adhesion of the coatings decrease with the substrate bias. After SRV tribological test we verify that the coating prepared under the minus 55 bias has highest wear resistance.
We got coatings with titanium content range from zero to fifty-one atomic percent in second stage. With increasing the content of titanium, the structure of the coating can be divided into three different types. When the titanium is within twenty atomic percent, the coating is the amorphous diamond-like carbon coatings. When the titanium is between twenty-eight and thirty-five, the structure of the coating is mixed with titanium, titanium carbide crystals and some of the amorphous carbon. When the titanium is above forty atomic percent, the property of the coating is dominated by titanium carbide crystals.
Through the study we can know that adding titanium contributes to the adhesion of the coatings and the coatings have the lower friction coefficient and higher wear resistance when the titanium is between three and twenty atomic percent.
We demonstrate that the hydrogen-free titanium diamond-like carbon coatings do have more advantages in tribological properties than conventional hydrogenated diamond-like carbon coatings. The twenty atomic percentage of titanium diamond-like carbon coating which flank wear is just about one-fifth of the uncoated insert that shows coated appropriate hydrogen-free diamond-like carbon coating truly help increase the tool life.
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