| Summary: | 碩士 === 逢甲大學 === 材料與製造工程所 === 92 === At present, the cathodic arc plasma ion plating (CAP) is widely employed in the industry to improve the surface quality and extend its service life. The industrial demandings also push new development of configurations of equipment and coating materials, such as multicomponent, multilayers, and superlattice coatings. Meanwhile, the coating materials available are also diversified into pure metals, Alloys, and compound ceramic coatings. However, the workpiece loading capacity and multilayer coatings still remains problem. The purpose of this research is to provide a new CAP method with Central-configured multi-arc sources (CCMA), where the array includes three cathodes forming a triangle pillar. Each cathode is located on the triangle pillar surface and independently powered by each arc power supply. Unlike the conventionally used cylindrical hollow cathode, this configurigation is beneficial for larger workpiece loading space and capable of producing multielement and multilayered coatings.
In this study, the CCMA CAP method is used to deposit TiN/ZrN coating under the different substrate rotation speed and the nano-multilayered coating structure is expected to form. The surface hardness of specimen is measured by micro Vickers indentation test. Scratch test is used to determine adhesion strength of coating, Scanning electron microscope (SEM) is used to observe the cross-sectional morphology and to measure film thickness. Energy dispersive spectrometer (EDS) is used to characterize film element. Crystal structure of the coatings is characterized by X-ray diffractometer. Experimental results show that the deposited coating forms multilayers (TiN/ZrN) structure as expected in lower substrate rotation speed with each layer having (111) preferred orientation. As the substrate rotation speed exceeds over 10 rpm, the surface coating forms nano-multilayers (Ti/Zr)N structure with each layer having (111) preferred orientation as well as the highest surface hardness. This is explained by the coherency strain effect. Due to nano- multilayer structure’s resisting stress acrossing the interface, it leads higher adhesion strength because of the difference in shear elastic modulus of each layer. This research proves the novel design of CCMA CAP method that can are highly flexible in coating material design and capable of mass production.
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