Preparation And Physical Properties Of Nanosuperhard Coating TiAlSiN

With the development of modern machining tool, Higher demands on the cutting tools(High cutting speed、Precision、High reliability、High feed rate、 Long Life and Cutting controlling) are proposed. Because nanocomposite TiAlSiN film has excellent performance of TiAIN (high temperature oxidation-resistance) and TiSiN (high hardness), it is becoming the research focus for materials scientists. The nanocomposite films can be deposited by different physical vapor deposition (PVD) method. Due to the high ionization rate, high deposition rate and well adhesion strength, arc ion plating is widely used PVD method. So this paper use arc ion plating and dc magnetron sputtering to deposit the TiAlSiN composite film. But the film deposited by arc ion plating has a rough surface because of the droplets pollution. And thus the performance of the film will be obviously suppressed. DC magnetron sputtering would produce film with smooth surface, but the ion energy and the ionization rate are reduced and thus influence the efficiency of the film formation. High-power magnetron sputtering possesses the advantages of cathodic arc and DC magnetron sputtering, so we also used the high-power pulsed magnetron sputtering and dc magnetron sputtering to prepare the TiAlSiN composite film. First, we used cathodic arc ion plating technology and DC magnetron sputtering to deposited TiAlSiN film. Using statistical methods of orthogonal analysis method, the effects of process parameters (negative substrate bias, gas flow, arc arc current, direct current and cavity body temperature) on the deposition rate, surface roughness, surface morphology, cross-section morphology, crystal structure and hardness were investigated. Analysis orthogonal experiment, the impact TiAlSiN deposition rate parameters in order of importance:the matrix negative bias> chamber temperature> Gas Flow> arc current> Si target current; influencing parameters in order of importance TiAlSiN film hardness deposition rate as follows:gas flow> chamber temperature> substrate negative bias> Si target current> arc current; parameters affect TiAlSiN film roughness in order of importance are:the substrate negative bias> gas Flow> Si target current> arc current> cavity temperature; parameters affect TiAlSiN film composition in order of importance are:the arc current> Si target current> cavity temperature> substrate negative bias> gas flow; eventually optimal combination of Orthogonal experiment for deposition of TiAlSiN film is A2B2C3D3E3.Then TiAlSiN films were prepared by high-power pulsed magnetron sputtering and DC magnetron sputtering technique, and the influences of negative substrate bias on surface and cross-section morphology, crystal structure, hardness and adhesion were analysized. The main conclusions are as follows: The surface roughness Ra of TiAlSiN film initially decreased and got to minimum value of7.26nm at-200V and then increased with the increase of negative bias. The application of substrate bias changes the composition of the film, wherein increasing of bias gave rise to the decrease of Ti content, increase of Al content and no obvious influence of Si content. The improved substrate bias led to a less and smaller droplets on the surface, more dense structure and disappearance of the columnar crystals. All the TiAlSiN films possessed the B1NaCl phase structure. But the application of bias caused remarkable change of the preferred orientation. Without substrate bias, the preferred orientation was (110) and it changed to (220) when bias of100V was applied. The intensity of the peak improved with the increase of bias from0to-200V, and the subsequent improvement of bias led to the decrease of the peak intensity. The hardness increased first and then decreased and reached a maximum of29GPa at-200V. The film hardness is inversely correlated to its brittleness. The change trends of the adhesion strength with bias was completely contrary with which of hardness...