The Research Of Key Technology On The AlTi Alloy Target For Application On Arc Ion Plating

Cathodic target is one of the key raw materials to prepare PVD coatings. The purity, density and microstructure of the target has significantly influences on the erosion of the target and the composition, structure and properties of the coatings. With the fast development of vapor deposition technology, the quality and performance of the target are improved significantly. However, the atoms of the target have processes of re-organization and re-grown due to the effect of the plasma during the PVD process. As a result, the application of the target can not be explained only using the traditional parameters (like purity, density and grain size). Instead, it is necessary to study the relationship between the parameters of the cathodic target and the properties of the coatings.In this article, the cathodic arc ion plating was used to deposit the AlTiN with two kinds of AITi alloy targets (Al:Ti=67at%:33at%)supplied by AT&M and GfE, respectively. In addition, AT&M AlTi alloy targets with different Ti grain sizes of 200μm, 125μm,75μm and 35μm, were also used in this paper. The arc spot motion of target surface as well as the properties of the coatings including phase structure, mechanical properties, tribological properties were investigated systematically as a function of the Ti powder gain size. The relationship of target parameters and coatings properties was discussed carefully. The main results are as follows:1. The cathodic current, deposition pressure and substrate bias voltage were optimized to prepare AlTiN coatings with a high performance.2. The AlTiN coatings were deposited with GfE and AT&M AlTi alloy targets (Al:Ti=67at%:33at%) under different intensities of the electromagnetic field. It was found that the arc spot movements on the surfaces of the targets were different in different intensities of the electromagnetic field, which resulted in different properties of the as-deposited coatings. It was supposed that the thermal conductivity of the target material is the main reason contributed to the affects of the targets on the coating properties, while the thermal conductivity is related to the powder grain size in the target.3. AlTiN coatings were deposited using AT&M AlTi alloy targets with different Ti grain sizes under the same process parameters. The effect of Ti grain size on AlTiN coating performance was studied. The results showed that Ti grain size can influence the arc spot movement on target surface during deposition, resulting in the different performance of the as-deposited coatings. The coating deposited with the target that has smaller Ti grain size exhibited a better performance.4. In conclusion, the relationship between the target parameters and coating properties is that the powder grain size of target material affecting the target thermal conductivity, which would influence the size and movement of arc spot on the target surface. As a result, the as-deposited coating exhibited different performances.